Also for task "6 league matches with starting line-up and subs having superb morale" to work, you need to have all players(including reserves) on superb morale !

About personal trainer, minimum is 40 tokens to use on a player if i'm not mistaken, to complete this task. And if you want to skip a task it cost you 25 tokens

A small advice, try to do tasks that are easier to complete and wait for the rest, because some of them link to other tasks.