Should I finish the main missions first?

[toky0]

Any idea?

[andressergio]

i had to with X13 so i could get the crossbow and new renegades that offer very hard lock pick with rank 9 stuff

[Sendai-Ono]

From what I've read, some side quests fail if you don't complete them within a certain timeframe during the main mission.

Apart from that: It's an OW game that's supposed to be played... well, openly. Doesn't rushing through the story take away a fair bit of the fun the game ideally can be?