As the title says really.

If the game moves onto to Chapter 2 do I loose access to quests I may have missed so far, and does it become impossible to finish some existing quests I have yet to complete?

No. There are a few areas that you can only visit once during the game (introduction Candlekeep, two of the areas (not Durlag's Tower) added by the expansion (both reachable only by talking to the right person in Ulgoth's Beard) and another area that would be a bit too spoilerific to mention but doesn't really have any missable quests), but there are no other restrictions on when you should finish side quests, as far as I know.

Great, thanks :)

there is something if you dont do it in a certain orders you wont have access to it, certain loot. If you would like the spoiler I can fill you in.. it is a quest that access gets shut off

No it's OK, I'll find out myself, don't want any spoilers :). I just wanted to make sure I wasn't shutting off large parts of the game by moving on to new chapters.