And yet you haven't offered a single example of what all these other mistakes are...
There are plenty. Let's see :
1- Fecking up Moyes season, chasing the whole summer after Fabre who went to Chelsea next season without much negotiation, then overpaying for Fellaini over his release clause on the deadline.
2- Spending shite ton of money on average players under LVG, making our spending go sky rocket without improving the team a little bit.
3- Giving those average players giga salary of money, like Rojo, Darmian, Blind that ended up with us struggling to offload all these deadwood as they don't accept pay cut.
4- Giving Rooney a giga contract which become a big problm after his decline that SAF saw from a mile earlier happened.
5- To show that he never learns, he went on and made the same mistake with Sanchez, disturbing the whole squad.
6- His policy in the market is spending on as much marketable players as possible without even thinking how the manager will use them. This started from Di Maria and Falcao, whom the latter LVG kept him on the bench for most of the season. This created a squad of mercenaries mixed by average players.
7- His lack of visison for the team. His stategy of appointing managers is based on panic decisions not plan. He hired 2 managers completely different from each other in the way they play, and both were panic decision after sacking the previous manager. He's not thinking of building the team based on certain way, but hiring the best name available and that's it. If Mourinho hadn't fallen out wih Chelsea, not sure what he would have dealt with LVG crisis. Not sure also what he would have done with current Mourinho crisis if Zidane wasn't available. He doesn't have any vision on building the team.
8- Finally, giving Mourinho contract extesnion midway in the season, just to refuse backing him 6 months later, then deciding to not sack him despite him not trusting him, leaving the team in nutshells. He basically wrote the whole season off before it even started.