As much as I hate those shitty skins and since they'll never be removed (as they're a VIP feature many players has paid/will pay for) it's useless to make negative comments about it.
As for the suggestion I think that it'd be a good idea to let everyone use those skins in duels like chainsaw and sniper. It'd be a good preview of some of the VIP features (and for me the most important ones) for players and encourage them to donate the server to use those features permanently.
I can even go further and suggest that let's do the same with races and let everyone use vehicle commands like /cc, /wheel and maybe even /nos If it'll be enabled which I'd like to.