Oh don't get me wrong i want everyone to be able to UNLOCK IT. Just not everyone use it at the same time or take up the slots for using it for too long.
Something i think they could do is have a 'leader rank' or something similar to BR from planetside 1 where you got a small portion of xp for everything your squad did. Now, in ps1 as you went up in your BR rank you where able to do more and more stuff like give orders over chat, call orbital strikes, etc. What they can do is you need to be a very high level leader rank, if not max rank in order to pull both TDA and dreads. This way when you see someone using TDA (or a dread) you know that they are not only a good player but an experienced leader as well. You can put other limitations on it like a long cooldown, expansive to pull, etc.
I'd leave it as an unlock solely for PVE-use, make it feel a bit like Space Hulk. I'm more worried about Centurions and how they might be added to the game.
Err i don't like that idea at all, i don't see why we can't use it for pvp. They maybe supper powerful in the lore but they can always tone it down a bit for gameplay reasons. Even in the lore they are far from unkillable.
In PVP if the maps are massive than TDA will be less of a prob. In PVE phasing to separate the skill tiers or stages can solve the lore prob as more important or the final push can bring out the best gear. Weather its PVP or PVE there are things to consider. 1.Speed) Slow, In movement, reaction time and relocating. 2.Weapons) limited options, can't change loadout in the field. Only Obliterators and Mutilators are the only ones can. 3.Power gamer's) even if we find a way to balance #of suits with lore, most will try to snag 1 asap by running through content.
To the issue of not being able to play your favorite class you have to remember that there will be varying levels for such classes. For example, maybe only the top tier players get to be the Chief Librarian in a strike force but there are several other mid to lower tier Librarians and Codiciers of varying rank. No reason you can't play a low ranking Librarian. Not everybody could be a Captain sure but if everybody is a Captain, then nobody is a Captain. As for Terminator Armor and the like, it seems to me that it won't be a system in which you play for a while and then "own" the armor in the traditional MMO sense. What makes more sense is to give each faction a finite amount of heavier weapons and armor to use in encounters. These would be allocated by the Chapter Master/Chaos Lord/Warboss/Exarch as they saw fit. But, to ensure that there's not too much of that type of authority in one person's hands you can create a middle ground type of system. After playing a while and amassing kills, XP, victories - whatever stat they're using to track success - you can create a higher bid to claim such armor if you so choose. This could probably be manifested in a type of resource players can spend to get such gear. The Chapter Master (with the help of their Captains and Sergeants) can only allocate armor to people with a good enough claim. Even then, at a certain point somebody could just spend an extra amount to claim the gear, overriding the leader's allocation of resources. The nice thing about this system is that it forces factions to work together to create a cohesive fighting force and something of a community. It will also have the cooler effect of players naturally having the potentiality to become more famous for their actions. In lore there are Space Marines that every marine in every chapter knows. Most of these are Captains and the like but occasionally Honor Guard, Sergeants, and Tactical Marines make the list for their deeds. Something similar would probably occur here organically. And it'd be really cool.