This is a very complex question... there are many many variables. Would Anakin have been ok? Would the Emperor have been defeated before becoming the Emperor? Would Dooku have been a bad guy? How much of Qui-Gon's attitude would the Jedi have believed? What would have Obi-Wan's career have been like? Would the whole concept of returning after death ever become apparent?
Nightmare.
What Might Have Been-?-
I say that had he lived he would have successfully trained Anakin as a Jedi. Anakin would then be less vulnearable to Palpatine and would not have allowed his feelings for the beautiful Padme to overcome him. And Obi Wan would not be remembered as the one who trained a future Dark Lord. Had Qui-Gon lived, Dooku might not have joined Sidious. It is hard to really know for sure but the entire Star Wars plotline would have been rewritten. 😉