Late as heck, but whatever.
Two minor things that irritated me a long while back when I still did some FRED: the Events editor, and using FRED on a laptop with no keypad.
For some reason I have a very, very ?BAD? tendency to end up with very long conversation events tied up as a single sexp event, particularly at the start of missions. The testing part for such a small thing is bad enough, and if I was already tired... I boot the mission only to find a sentence not being said (because the required sexp tags were missing for that one line and were not added), or the wrong ship saying the wrong text (because eyes went bad while looking at the event chain).
As for the keypad, it would be nice if the controls could be changed. Having to use the function key every single time to move and turn the camera while FREDding was a big de-motivator to finishing missions, considering it's no good to sit on a chair working on a desktop for very long hours.
I didn't even do the FS2 tutorial, what horrendously little I know of FRED came from playing around in the FS1 version and trying to make the player use Shivan ships and allied Lucifer and ultimately failing, such was the code and zero understanding of VP files back then
I somewhat miss multiplayer testing. But the last tester I had is all into the latest console and PC games now with new friends
and I doubt he's as patient now as he was back then, what with using Hamachi and all that (pointless to connect to FS2NetD because of ping) in addition to having to create rushed-edit versions of stock FS2 multi missions just to test new weapons and assets. IIRC back then I ?think? I went as far as to even test beam weapons on what-was-that-fighter-from-the-Federal-pack, and then came the game-killing beamspam lag and energy deduction totally not working as I thought was intended (not sure about the codebase now)...