I am a liability as infantry. I managed to kill 4 of us while trying to lob a grenade over a wall.
Ive been using medic but I cant get the hang of dragging yet. I would like to try other back line roles but none are ever available.
How can I get access to these roles?
Can I suggest taking a rifleman role and supporting a specialist, rather than taking up a specialist slot yourself? Mistakes happen. If you need some practice with grenades, there's a range for that. Try, try again, and then get back in there.
Up until my break from Squad (due to parenting) around 1.4 years ago I was regularly playing Engineer and Medic while trying to establish some gravitas as a Blackhawk pilot, and I always played aggressively when ground-pounding. Pushing hard and using smokes to conceal is a big part of that. If pulled off well, it could also give you an opportunity to select "drag" where you need it, drop charges or whatever. It sounds like you just need to figure out your muscle memory and go from there.