today, we can't test weapons, and i find the testing characters option usefull but pretty annoying too.
why not add the possibility to test everything, unlimited, in the solo game ?
wich is, i think, pretty anecdotic for now.
you can even add an optionnal IA antag on solo mode (with eventually the possibility to chose who we'll fight).
so we'll be able to try characters and missions against both pve and "pvp" and it will add some usefullness to solo mode.