That's what levels are for, also wolfadmin should ideally show the date of first appearance in !finger or such (should probably attempt to add that)
I saw that too, but that's what admins, like you, are for. Punish people if they do xp-whoring (though makes no sense for tm).
People just got used to it, but it doesn't mean it's a good thing, server can get extremely disbalanced due to certain changes, like spawntimes, and ofc max skills. Imo average player wants to just have fun game, and skill upgrades (or not) have nothing to do with it, more over, having skill upgrades on, to my experience, keeps people longer on the server (not that this is an issue for tm due to monopoly). Gradual upgrades makes game certainly more pleasing, especially if you have played campaign mode. We do actually want to get campaigns back on track, by introducing dynamically composed campaigns, to allow different map sets (to compete with mapvoting), that would indeed make it even more closer to the vanilla experience.