I agree with you and yes I am not very good myself YET!!! It takes practice. “The difference between the novice and the master is that the master has failed more than the novice has tried” -unknown
What I do is I will use ether beeswax and neatsfoot oil concoction or Aussie leather conditioner on both sides to prevent water from soaking back in th the leather and leaving marks.
I would get the class 4 it would be better than the 4500 b/c the 4500 wables and the class 4 doesn’t plus the class 4is Built like a tank. Buy a new not a used unless you are or want to be a sewing machine mechanic.