I would say..
Medium rates -Not too fast lvling.. but decent enough you dont get bored, e.g 40+ = a lvl every 4/5 days kinda thing, 50+ might take a week per level, depends on how you like to level.
Rare drops rates - By rare i mean, up to a certain level, decent kits can be obtained of decent boss's, but to get a good drop.. requires a group of maybe 2/3, or a good kitted high level char.. make sure para/pro/rev/clear/tele are Very rare also, you dont want 20 people out of say the 30 usercount having these rings, you want the to be special and unique.
Stats - Kept very much medium/low stat e.g Dc 150ish/Mc70ish/Sc70ish @ lvl 45+ (not 400 or summit stupid like that) remember if your sticking with the med rate.. there arent going to be many people over level 55, give you a lot of space for more kits.. special items.. kits the level up and still have decent stats. Makes pvp a lot more fun as its not over in the first few hits.. also gives wizzy's a chance in fight... also makes you want to work harder for that next ring with an extra 4/5 dc over your current.
Good GM's - I know this is hard to find today with the community that play mir.. i dont blame some GM's for hardly loggin on servers, the second they do.. they get spammed with complaints about something or other.
Spells - No multi class spells, there are seperate class's for a reason, the only one i think is fair would be Rev.. but even make that a fairly rare book for wiz/war to get.
Pets - Take it back to the old days.. Tao's get their summons, wizzy's have their Eshock for a reason, even if you add a taming room.. its better than all class's getting pets.
Boss's - There should be a fair amount of boss's, not overkill tho.. also it would be nice to see group hunting, guild hunting area's.. By group i mean 4/5.. by guild i mean 10+(If you got the usercount), it doesnt mean that it will take the full 4/5 or 10 to kill the final boss.. just that it would take that ammount to reach the KR.. might loose a few on the way.. this is a lot easier to do with lower stat server.
Quests - Now quests is the tricky one.. a lot of players dont think them, some do.. so what you gotta take into account is, not to make quest based items ( if you are using items as prize ) too good compared to normal items.. yes it might make some of the player who dont usually quest want to, but it will also annoy some of the players who dont ( i know you cant keep everyone happy ), so basically keeping the prizes fair.. also not too many quests to start with.. 4/5 is sufficient for release as long as they are not too easy to do, which brings me to my second point, make quests HARD.. i mean really hard.. who wants a quest that " Go collect 10 of these " and bang you get an amazing ring.. if you are using an amazing ring say a special para that requires certain items + a para, make those items really hard to get.. as the para itself will already be really rare, make the accomplishment of the server a lot better.. keeps the players interested in them aswell.
Gold - Now this is where i think a lot of server fail these days.. people walking about with " Billions ", i think gold should be kept to a minimum, where maybe at some points.. you have to scrimp and scrape to buy pots to hunt.. its all in the fun of playing, this is where you can implement gold quests also.. say you can do it once a day, and you a.. yes i said it.. goldbar!. Wooo! But it keep economy lower.. and also make money well worth using for items, and give MirKing his purpose back.. a chance @ a gold chest + 3 bene's !
About all i can think of just now. hope it helps