The OP posted again as I was typing this, so for any inconsistencies see the area labeled EDIT: at the end of the post.
Here are the points the OP made, in an easy-to-understand format. I will make my own responses to them AFTER I finish listing them out.
1. Assassins have very little self-healing compared to other professions.
2. Daggers have a low base damage, and should be buffed to 15-22 like a sword.
3. Assassins are meant to be played in a hit-and-run style, yet have few skills to support this. Thus, their armor level should be increased to compensate.
4. Assassins have very few blocking or evasion skills, which is a problem as they are melee characters.
5. Shadow Form is an awful skill in that it takes up an elite, and once it runs out you're dead.
The rest is pretty incomprehensible to me, might I suggest you look at Rule #9 in the Forum Rules, OP?
And in his second post...
6. The Energy cost for Assassin skills is too high, and combos aren't possible when you expend 35 energy to do one combo and get out.
Anyway, here are my responses to the OP's points.
1. Assassins aren't meant to need much self-healing. They are supposed to Shadow Step in, get a quick combo off and then get back before they can take too many hits. In PvE this shouldn't be a problem as long as you have a decent tank. Also, see my response to point number three for more info.
2. Dagger damage is fine. Without skills, an assassin has approximately the same dps as an axe warrior. This was tested on the AL 60 dummies in the Isle of the Nameless.
3. Here is a list of all the hit-and-run style skills the Assassin has, at least those that I can think of off the top of my head:
Aura of Displacement
Death's Charge
Return
Recall
Caltrops
Dark Escape
Shadow of Haste
Dash
Spirit Walk
And I'm sure there are more. As you can see, there is no problem with the hit-and-run capability of the Assassins. If anything, just Death's Charge in, combo, Dark Escape out. Spirit Walk is good if you have a Ranger or Ritualist on your team. The Assassin has plenty of hit-and-run skills.
4. I already said that Assassins aren't meant to take damage. Thus, blocking and evasion skills aren't needed so long as the Assassin can actually be played well by the person using it.
5. Shadow Form is actually the answer to your prayers, OP. Cast it just as you go in, get a combo off, and run back to your backline before it runs out. A Monk or someone can then heal you while the enemies are still fighting the tank, provided the tank is actually doing his job.
6. I play an Assassin in both PvE and PvP and never have an Energy problem. Why? Because I choose my skills carefully. Way of the Lotus is excellent energy management, particularly in PvE. I also generally prefer to skip the lead attack and go right to the powerful attacks by using Golden Phoenix Strike, which is an off-hand attack that doesn't need to follow a lead attack. And about recharging and downtime, what do you think Assassins are supposed to do after the "run" part of "hit-and-run?" They wait and regen until they can spike again. That's what they're best at: spiking one target. Thus, energy should never be a problem.
So no, Assassins do not need a buff. They are perfectly fine as-is. The only reason you see them dying so much is because many people who play them can't play them well. Their damage output is top-notch, and their armor is lower to act as a balance. If played correctly, armor shouldn't be a factor at all anyway. Assassins have Energy management skills of their own, so that isn't a problem either.
Now, and I MUST stress this...
View Rule #9 in the Forum Rules section as soon as possible, OP, please. Adhering to it will make everyone's life a little easier. Though in your most recent post you seem to be adhering to it MUCH more than your first two.
EDIT: OP posted again as I was typing this.
Now, I agree that Death's Charge has a long recharge time. But if you play well and let the tank gather aggro before going in, then you won't need to shadow step anyway. You could always use Dark Escape as a panic button. For PvP purposes, Assassins are used as solo base-gankers. They are FANTASTIC at this because of one skill: Aura of Displacement. It's a maintained enchantment, but all you use it for is to get up, unleash your combo, and get out while the degen kills your target. Its recharge is 20 seconds, but you'll be recharging other skills during that time frame anyway.
Also, read above for the argument on dagger damage. Trust me, it's unnecessary. Sins do enough damage as it is. Besides, what's gonna hurt more? A 4-inch dagger wound or an 12-inch sword gash?