Yep, also good points
I also think the question of a player potentially being shit, injured or going on strike - could happen sure, but likely outweighed by other players exceeding their value either in transfers or playing ability, and not being lost on a free as you say
£10m a year might seem huge, but in 8 years it may be fairly standard. Flip it around and Cheksea might be getting these players fairly cheap in the long run.