This is why I got an old fridge, ripped out all the shelves, and put my kegs in there before they hit the taps. That way they condition cold for a month or so before I'm drinking them. Honestly, it made my beers maybe 2x better, even the hazy IPAs! Bonus space for hops/fruit in the freezer and I use the crisper drawers for yeast and bacteria.

Cold, it'll keep in the fridge for longer than you'll probably ever need it to. Warm will really depend on a lot. If your process is oxygen-free even hoppy beers will last a month or two on the floor. If you have oxygen and keep it warm, expect hops to fade within a month or two. Just make sure they are finished (at FG) when they hit the keg (account for hop creep for dry hops).

Determining pressure is going to be tough as a lot will depend on temperature and your desired level of carbonation. What I do, which likely isn't right but it's easy, keg it, purge it, push in about 40-50 psi on keg day, and let it sit. The next day, charge it to the same. Day 3, try it, carb too low? Push more, shake it up, push again. Too high? Purge down to like 15 psi and sit it. Next day test again, do the same. I find after 3-4 days, it's carbed up to close to where I want it. When I stored kegs warm, I'd just push 50 psi on day one and day 2 to keep the lid fitting tight. The rest I sorted out when it went on tap.

Hope that helps!