Do live events and player favorite events return?

Yes,

Live Events usually return once

Player Favourites return multiple times

So far Simchases have returned once

Sim Chases and Player favourites have to be re-done in it's entirety,

Live Events, you only have to collect what you missed

I have not seen a Live Event return twice, so if it have already returned, chances are that it won't be back

For Player Favourites, find a list of all the sets/tasks and make a schedule, set timers, plan what to rush, make sure to have the right numbers of adult sims free to do the quest etc.

It is quite expensive to rush the multiple sim task, so try rushing tasks for one sim

Count on spending around 100 LPs to finish unless you're one of those people that need no sleep

For Simchases, count on paying a quarter of your total funds for daily lessons or around 150 SPs