Still sounds unsettling. I hope you can find the reason for that.

Are you the only in your group to frequently detach your fingernails? Because I have never experienced or heard of something like that so far.

Congratulations! Shiai is a totally different part of Judo. So it is completely normal to learn everything anew. No amount of Randori could have prepared me for my first tournament… The intensity and ability which experienced players show made me very humble.

Try to relax. Being tense will increase the odds for injury.

One is a koshi-waza, the other a te-waza. They are indeed quite different in theory. While in actual fighting it might be hard to tell which technique was actually applied. But you should choose the one which feels better for you or whatever grip you can get. You don’t get more points for throwing one or the other.