How does DoAsc work?

I am no guild wars noob (I have played for over 2,300hrs), around 800hrs of that I have dedicate myself to speed clears. I have done most of this in dungeon speed clears, learning 95% of all the roles and positions needed to speed clear dungeons. I have done shards of Orr, kathandrax, vloxen, all of slavers, oola, boogroot, ooze, cathedral of flames and many more.
I have also invested some time in Fowsc being a 100b and UA monk. I did prenerf UW chamber and postnerf E/R T1. I know how this game pretty much works except I am not clear on very advanced topics (pulling - enemies rotating counterclockwise when they are regaining HP and such in the sc thread I just read) but I know most else. My question is, I am pulling my Mesmer through nightfall so I can DoAsc. I obviously won't be a caller off the get go but what should I expect in DoAsc?

You won't be able to join a DoASC unless you are part of a guild that is capable of it. Since you are asking this question here and not on your guild forums, i would assume that you are not in such a guild. DoASC tactics are complicated and exploit ai and the way enemy pathing is coded almost constantly. As a mesmer, should you find a group, there IS somewhat of a "bitchrole" which will allow you to become more familiar with tactics and such, but its still a somewhat involved area to get in to.

I have heard that this role is the mimic Mesmer correct? Assuming there is no trouble entering a DoAsc guild (I have some friends I can talk to) is the combat (at least for the mesmers) similar to a manlyway spike for Fowsc?

Since when is Frostway/Glaiveway considered DoAsc ? There are enough guilds wich are capable to do it 3x as fast as Frostway in HM, the way they use is the real Doasc.

If you want to start off with DoAsc, don't even get started with Frostway, it only sickens your mind, try to get into a starting DoAsc guild and build up from there.

To answer on your qeustions:
- Almost every doasc guild uses his own tactics and builds, so in the one the starting role could be "mimic mes" and in the other one it could be SS necro for example.
-I geuss you could compare the combat of the mainteam in FoW with that in DoA, the tank balls up, mesmers spike with EoE up, monk seeds on emo to keep tank/emo alive. But offcourse is DoA a totally different area with different qeusts to do.

As others have said, the only way to go in learning do doa is to join a guild that does it regularly and is willing to teach new players, if you unlock all the skills you need and use both halves of your brain then it won't be too hard to learn any of the mesmer or monk roles, and then you can progress onto the other roles if you want to.

Doing DoASC good, by that I mean, knowing what is going on, and how to adjust to every possible outcome also requires a very extended knowledge about how this game, and especially AI works.