I thought that once beer was kegged and under pressure, it was good to go? Wrong info? Should I have kept it at a stable, cool temp? Loved to hear some thoughts on this. Thanks
It is good to go. Just like a bottle of beer. If you treated a commercial beer that way, it likely would have had issues as well. Imported beer often suffers because it was on a boat. You just simulated part of the journey.
If your beer has some trace microbial action going on, keeping it warm will just encourage them. Kegging helps it from going stale as fast, but it will still eventually stale. Heat, light, mechanical agitation all encourage aging, as do frequent temperature swings.
Keeping it at serving temperature will encourage you to finish it faster. Keeping it at fridge temperatures will help it remain stable longer. Either one is preferable to just letting the keg sit around.
If the beer is now off, dump it. Take apart your keg and give it a good PBW soak. Scrub the serving tube, take apart the posts, remove the gaskets, inspect and clean everything. Sanitize well, and then get back on the horse. If you had a good beer, you can make it again. Take care of it, and when it seems like it's losing something, take it to a party or something and encourage people to finish it.