After reading both your posts you seem to have a suitcase full of doubts about what you're letting your self in for.
Going off tack for a second I watched an army recruitment prog on the tv the other day. A female was handed an SA80 rifle and burst into tears when told it was a tool to kill! She hadn't obviously done her homework. The job of the armed forces can include killing! It's part of the role. Either directly, firing the actual weapon or, indirectly. Directing an aircraft to its tactical objective which may mean weapon release and again, killing.
So. its healthy having doubts, training is hard, it's meant to be. It will push you to do things outside your normal comfort zone. However, rest assured, thousands have been where you are now. If you talk to them, (us), we will all tell you it was an experience we wouldn't change. Most would do it all again.
Carry on asking questions, it's how we discover what is right or wrong for us.
Whatever you do make sure the job you finally decide on is the one you really want to do. Changing later can be difficult or impossible.
Good luck, stop doubting yourself and choose wisely.