i'm still somewhat new to this engine, i was a big scripter for half-life.
I believe the set is used for quick variables and the seta for arrays and more complex commands/code.
I'm still inthe trial and error part of scripting... some code is easier if you set a toggle some are better if you set for a key press. I wish they allowed you to bind to - and +. Then we could do some really complex scripts.
IE in CS i had a script that when i hit a key and help it down it'll buy a nade then prime it. Let go would throw it. You could spam nades for the first min (buy time ends then) and since they damage through walls it was great in maps like assualt. Alas you can't do that, as far as i know, in this game.
PS. I don't use these script anymore. No need, once i learned the timing and moves myself. These are old, and are being used to teach others. No one is forcing you to use em. Just want to show you what can and can't be done. Better that you learn this now, then start false theories and spread misinformation.
I would like to die peacefully and in my sleep, just like my grandfather. Not screaming in panic like the passingers in the car he was driving.