[I need a new challenge.....]

Have you tried a proper Lower League Management game? Non-League is a completely different beast to a top 5 league. 

Otherwise I would suggest a Glory Hunter game where you attempt to win the top 5 leagues + world cup + Champions league.

[no longer on favoured personnel at my old club]

Basically favoured personal gets cleaned after a person leaves the club for some time. This is to simulate the idea that the person was respected whilst in charge but did not generate enough feeling that they would be particularly remembered after they leave.  

[Foreign Youth Players]

Brexit rules will apply. I would recommend checking the rules section for your league. Generally though they either have to be a consistent international (unlikely for a youth player) or you will have to meet several criteria. Transfer fee is just one of them. The wages you pay to the player often needs to be higher also (average for a first team player for example). The reputation of the league they come from also matters. 

Check the rules section and think whether or not the player can meet the criteria.