In Premiere Pro, can I change the audio latency in a project that has already been worked on?

Using PPro, I have no audio lag, everything seems to be synced up.

My latency is the stock 200ms, but I'm assuming if I change it to 50ms, it will be tighter?

system: win10, 32gb ram, ssd's, Ryzen 7 ...8cores.

Can I change latency in the middle of a project?

Should all future latency settings be as low as 30ms for best sync?

And the big question: 

Does the latency setting affect PPro playback only or rendering only or when burning to disc, or all of it??

Thanks!  Been Googling all night, can't get a defined answer.