Transitioning Over to HM -- Any Help?

No.

First of all, neither of those is a great build for general PvE. Sabway is designed for 4-man areas, so it has a lot of compression and compromises that aren't necessary for 8-man teams (even if 4 are hench). Discordway is downright mediocre.

Second, and more importantly, your problem is that you don't understand the game mechanics and monster design well enough to succeed. Ultimately, you will have to learn that. Sabway/discordway won't help you learn. They will only give you a small, unearned boost of effectiveness. As soon as you hit a patch those builds can't handle, you'll be right back to square one. You simply can not go around screaming how easy this game is and how people that shouldn't be able to win win it and then make this drama.
Disco and Sabway will handle pretty much all the content in this game. It might not be the most efective way of doing it but it will work.
And if nothing else - it gives the players a chance to actually win instead of failing continuously which in turn removes a lot of frustration and it gives the player the chance to experience content and learn.

Those two teambuilds are completely sufficient ways to experience HM.

Lastly is experience... my first few tries at HM had me shaking my head & saying NFW... now I can't see doing NM. THE essential part.

Ive found that a good way to get this experience is to tag along with people who know what they are doing, for missions, and to "solo"-vanquish easy areas (~50 npcs at first, then build up) with a 3-necro-team.

It's a pity that only certain builds work in HM, it seems, but I suppose that's just how the metagame goes. Some builds work better in HM than other builds, however this does not mean you need to run them.

In HM you need to be able to do some serious damage. Foes have more health and higher armor. When you fail first make sure you were killing foes fast, only after that look at defense.
Don't start out in 4 player areas, those are relatively hard compared to 8 player areas.

Make sure you have the best equipment you can afford, specially runes.
Have as much armor/health runes as possible, try to avoid superior runes unless you need to use for a breakpoint. And compensate as much as possible with vigor runes.

Now some comments on damage mitigation.

First of all, make sure the team understand that the monks are there to keep players doing damage, not to keep them alive. Keeping players alive is only a part of keeping them doing damage.
When looking at builds look at what disables your team from doing damage. Counter this. I'd say the main problems are conditions like blind, cripple, daze and such. Most conditions are annoying, but you can outheal them. Next some hexes here and there, but most are not that bad. Sort condition removal and hex removal out first.
Only after your monks decide on this they can look at straight healing and protection.
Make the team understand that only one or two players should take damage if possible. Those players should have some skills/equipment that prevents some damage (+armor mods/runes/skills, shields and such). The rest should keep back so the healers can focus. When aggro is broken it's time for the monks to use skills like Protective Spirit and Aegis to protect the casters of the team. Using PS on someone who's dedicated to holding aggro is probably stupid (mitigate by other means), unless there is a huge risk of armor ignoring spiking.

Mitigation also includes aggro control, learn mob movement and how to pull only one group at once.

Seek for skills that prevent damage, not only on your monks but also on other professions. A minion master is always good, adds both damage and 'cannon fodder'. But an damage earth ele with one or two wards (keep players in them though) is also a good choice.
But remember, stuff that died cannot do damage anymore. Keep your team's focus on damage, not on defense. Only a few areas need additional defense or a specific team build (Rotscale is annoying to kill with a 'regular' build).

Also remember that sabway/discordway are not easily played by human players. Try to understand how they work and what you can do and cannot do with human players to make them work (are you on TS/Vent for a Discord Spike, can the 'healer' play both healer and damage dealer at the same time).

Good luck, you will find out in a while that HM isn't that hard after all if you learn some of the basic mechanics of the game

These aren't jobs that particular characters do while everyone else does damage or heals - these are the jobs that *everyone* does while dishing out damage or healing in between. When people are thinking in these terms you don't need to have particular strategies or builds because it will just work with rudimentary tactics (pulling, focusing dangerous targets). Excellent post! Definitely agree with these comments. I laughed when the OP said the Elementalists in their guild would be disappointed. Trust me they can be more than useful in HM. Eles have tons of options with their large energy pool, especially when you start adding in PvE skills. Stuff you might not use in NM since you don't need it becomes more important in HM, like snares or wards for example. Experimenting is a fun part of the game, especially with other dedicated players to discuss things like what went wrong last time. Good luck.

The big stumbling block in transitioning to hard mode is that it forces you to play the game on a more abstract level. Normal mode you can largely bludgeon through with 'damage and heal'. Hard mode forces you to capitalize on abilities that are a level removed from that - disruption and shutdown. These require a good bit more precision than damage and heal, but ultimately provide a lot more power. I wish you were right, but actually even in HM you can usually just bludgeon through most things with straight damage and two pure heal monks backing you up.

....
Only one other player in the guild can grasp the concept. The rest are more casual players, and may take time to start having "less monotoned" builds. Our elementalists for example carry 7 attack spells, but don't consider other skills as better options (they still only get off aoe-ing helpless enemies). I think until the rest can start thinking in terms of how to help the team mitigate or increase damage output, HM is gonna be a threshold just too high.
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As it is, they can barely pull off a NM mission successfully on their own, and I often have to suggest skills they should bring should I lead the mission. molepunch,

I'll give you some additional advice from my personal experience.
When you like to play HM more with guildies don't bring them all at once.
Just take the one player who understands and bring one or two other guildies. Fill the rest of the team with relatively fail-safe hero builds.
This increases the experience more than failing over and over again because 'the team build' doesn't work.

If you like to play some HM outside your guild or with a minimal number of your guildies feel free to PM me here on guru.
I don't play often anymore but am still online once in a while.
And perhaps more important I can introduce you to some players who have been playing HM for a long time and who always like to meet new people to tag along for some fun.

I wish you were right, but actually even in HM you can usually just bludgeon through most things with straight damage and two pure heal monks backing you up.
With consum and PvE skills, yes this is too true.

Unfortunately bringing two heal monks won't be the best way to go imo. You need prot of some sort. Red Bars up was great in NM, but a significant area of HM will need more, especially if you're pugging.

which is better for HM ? No simple better

Weakness is defensively very strong as it reduces base-damage from physical attacks to 1/3 very usefull against melee (and archer) mobs, not so against casters.

Cracked armor is offensive, it increases non-armor-ignoring damage by 41%. If your party brings a lot of armor-ignoring damage then this is not so effective.

I've a question regarding weakness and cracked armour .

which is better for HM ?

AoE weakness - Enfeebling Blood or AoE cracked armour - Weaken Armour

Enfeebling blood - 10% hp sac, 1 energy cost, 3/4s cast time, 8s recharge

Weaken armour - 5 energy cost, 1s cast time, 5s recharge Cracked armor isn't as good as Enfeebling blood. Weakness is so good for survivability that every team should have some source of it.

Cracked armor is meh. People don't use physicals compared to the popular necros and monks and rits. And the benefit isn't too impressive.

People don't use physicals compared to the popular necros and monks and rits. And the benefit isn't too impressive. When it comes to damage dealing, only Necromancers can compete with physicals in a PvE setting (and even then the Necro depends on physicals for it, be it MoP or OoU).

However cracked armour is of small value to physicals. It is only of real value to Elementalists trying to output some damage from their elemental skills.