I am using lvl 4 trainer with low salary and fitness, and i am pleased with my results. About u r PR, again 4 lvl is fine, just try to buy a low salary 1. Considering that u r team is weak, then national appeal is useless for u couz is giving u a boost on the away games, but what u need more is to win the games on u r arena.
About u r trainees, yes its a good idea to sell them, when u r ready to replace them with better players of course. Being on ur draft position is possible to get more than 1 good trainees, so why not?
Join us on the chat if u want. Usually me Ekleptismenos and Pathos we are there.