Spoilers obviously but other than the Citadel closing off some of the fetch quests are there ever any points where other stuff becomes unavailable? Given how late in the game you get Tali I'm curious how much I can postpone to do with her when I suffer through a Sheploo run.
Anything you get before the Citadel Attack, do before Tuchanka:The Shroud, INCLUDING T: Bomb, except for one mission triggered by an item in an N7 mission. It'll say something about finding a person to use this item in the journal.
Do the two Rannoch missions (General and Geth) before Priority: Rannoch.
Do everything else before assaulting the Cerberus base. It's the mission after the one with Miranda and her *spoilers* family.
AFAIK, anything not falling into those categories can be done at any time.
Once you get laid you're at the Point of No Return.
Crap, thats a dilemma if ive ever heard one. On the one hand, you get Skyrim early, on the other, you have to live in Arkansas.-Jadex9