I can purchase stocks at LCN website but the BAWSAQ is still under maintenance, I've completed 45% of the game and can't buy stocks from that website. Am I missing something? Do I need a special mission to unlock it?
BAWSAQ is influenced by the online community and it's likely down due to server loads. Games as popular as GTA V almost always have connectivity issues the first week or two after release so it's probably related to server load issues. Rockstar is also aware of the issues with BAWSAQ and you can check this article for updates it's current status.
Once it is is back up, if you need any help with the stock market here's a guide I found useful.
I'm only providing what I know, but I've had the BAWSAQ available since the start, I've even purchased shares in it already (in preparation for online becoming available). I don't even think I'd linked up by Rockstar Social account by that point but maybe I had. So long story short, I think it should work for you just maybe you keep catching it on a down time. I know I haven't been able to get SnapChat working because it was having problems, same with flight school leaderboards.
You have to sign into the rockstarclub for the BAWSAQ to work. That's it
Following on from some advice about getting all characters to buy shares in a specific company before completing an assassination mission, how do I actually quit a mission? There's only two ways I can see how:
Save just before starting a mission, and then load once it's started. The downside here is I need to remember to save before every mission in case one turns out to be important for the stock market.
Somehow fail the mission, preferably without committing suicide, where I'm then given the option to Exit.
Unforunately those are the only two methods.
However, in regards to you forgetting to save before, if you have autosave enabled, just load the autosave and it should load the game before you started the mission, but after everything else (it saves when you complete missions, buy clothes, mod a car, etc.)
Pause the game and go across to the online section where you find 'Find New Session'
this will also let you automatically allow you to save the game