Coolers pretty much never make a difference anymore as far as I'm aware. They used to at least have different distortion shutdown resistances, but they aren't affect by distortion damage anymore.
As for power plants, the only time upgrading makes a difference is if you're going for a stealth build or if your ships loadout manages to exceed the power output. An easy way to check this is to look at your loudout's power requirements on erkul.games
Same. It'd be nice to have early access to new patches, but at the same time I'm not sure I'm up for putting in the time and effort to make detailed bug reports on an even buggier version of the game.