Agree, but once you are a Vic club and in the top 4 the amount of talent willing to come to your club easily surpasses any non vic club.
You can also easily fill holes in your list e.g. target a forward, back, inside or outside mid, when a non vic club don't have the same options.
Therefore, it is easier to top up as a vic club, when you are in the premiership window, or extend the premiership window after winning a flag.
Sure but all of this is an opinion and not provable. In theory lower placed clubs have more salary cap to spend.
I also haven't noticed any kind of issue with non-Vic clubs attracting or retaining players:
Port picked up half a spine last year, rarely lose anyone they want.
Eagles almost never lose any players they want. Ditto Brisbane and Sydney.
Crows have picked up Dawson and Rankine who are premium players.
Freo have an issue with player retention but that has a bit to with recruitment IMO, tend to have lots of the same type if player.