1st) yes but make little difference between +4 and +16 or give information on web (on some servers you dont even know how much + does palyer have, when one have yellow color, another red, next player green etc.)
2nd) Make 1 custom armor set for heroes only. Stats same as S armor, make it on max ++ (result = heroes will have nice looking armor with stats of max ++ (for example +16) S armor for olympiad period (programme it as oly weapons for auto disable).
3rd) for everyone, 1 weapon set. Improve stats a bit, for example +20 p.atk +20 m.atk to weapon
4th) Tatttoo for p.def +5-10%, tattoo for m.def +5-10% (ppl will have both for oly)
5th) Custom mobs for farm items, make RB jewels for GrandBoss drop only and for a lot of vote reward, make custom RB for farm items, clan eggs, clan reputation item
If you want great server, dont go over +16 max enchant :)
If you are thinking about donate, make custom armor set +0 for 10-15 euro for example (not so expensive), I can tell you, if there are 300+ players on new server and I would be the only man with custom nice looking set, I would pay for it and help the server :) You can also make custom wings or hats (without stats) for 5 euro (nice looking armor + epic wings = 15 euro and feel like a god on server) O:-)