I noticed Blender is defaulting to making a temp folder on an HDD drive. Would it be noticably better if it were on a SDD?
Welcome to BA 
It will be slightly faster to read/write, but in this case, I doubt you’ll ever notice a difference. The temp folder isn’t doing massive data transfers
It depends… the standard output folder is /tmp/ and if some doesn’t changes this…
But in general there are only the autosaved files (MyFile_autosave.blend) and the last one (quit.blend). (Disk caches if used are in the path of the blend-file.)… and any crash data…
Just toss a coin which one is better and live your life happilly 
