Developing the OP ideas and taste for solo playing, how about mir without guilds, without possibility to group? Or if grouping would be allowed, how about if there was some distinct penalty for when pple grp up? Doesn't that make sense? The idea is that pple would not grp to rake in exp when leveling, they would grp only to defeat some boss and even then it would be made that the bigger grp, the higher penalty of some kind, even affecting (lowering) effectiveness of spells, skills...
I like when mir is full featured by which I mean there are all those sideline entertaining things like casino, lottery, Mystery cave (which finally got added to Chronicles server but with stupid euro admission times), more places like Ghoul Cave (but better opening times again, on euro it was stupid), Connecting paths, the more the better, some could be made very challenging to pass through - no RTs - (I still remember char porcelain being (perhaps) first on Phoenix server to make it through between ST & Sabuk (in those days as we all know, it was very much limited how many pots we could pack along) - very much liked hidden entrances in SW, should be more like that all around mir caves, there is nothing more disappointing than finding a doorway deep in some cave and it does nothing, is not active. I is exciting to map out where all those connecting paths lead, could be secret entrances on all sides to it also, or make one visible entrance someplace as a hint). One point of CPaths is mixing of mobs from connected caves which can make for some very interesting hunting. It could be that the mix would go from almost zero to hundred % - leaving ST by CP you would get only ST mobs but as you came closer to ZT for example, you would more Zumas until at ZT the ST mobs would almost vanish and all would be ZT mobs. There could be other mobs mixed in as well as sprinkling on the cake, even some stray midboss with irregular spawning time LOL
There was more of these little features in mir, can't recall them all, some as I said could be developed into bigger things. It makes mir more than just strait leveling to next armour point (22/33/40 etc). Speaking more fully featured mir, with all kinds of trimming, I like the idea above about skill books, that to get skill level 2, you would actually need to get in drops skill book of that level. So instead of single book for a skill as it is now, there would be three books.
As to AFK skill leveling, I am not quite dead set against it but providing town trainers goes too far IMO. I don't want to be making some dreaming suggestions but how about making all towns 'no skill leveling zones'. In addition if that could be implemented, how about limiting some skill leveling to caves only and moreover to caves that are appropriate to the char level (so you couldn't go level '33' skill to Oma cave, for example) But it should be individual, I recall leveling warrior SD skill outdoor on small mobs in Mongchon, as that is skill which you don't use often, more exactly you don't need to use it often and leveling it while hunting would take ages, most folks would never level it to max if they didn't make it a point to level it 'artificially'. Even town leveling might be ok as it adds to the atmosphere of town life, I think some pple would miss it, but trainers are silly.
There should be more caves in BC style by which I mean caves that are, or that give a sense of being spread wide on one level, not floors that go deeper and deeper. I am not sure if others actually see it as I do but in BC all caves to me are on the same level, it is achieved by those transition places and by the way caves are interconnected in many ways. From euro times, 'BC is mir' in my eyes. Also, I suppose it is OK to have those geometrical caves like ST WT, ZT, PT... but they don't provide as rich, varied gameplay as those caves with irregular wall with all kinds of nooks and all that which allows for various strategies. Caves like BC take time to figure them out so you don't get lost in them and that makes it all the more interesting. You pretty well can't get lost in those geometrical caves that are stacked and with fairly simple door logic.
Mir has three kinds of players, one kind puts in punishing hours and stamina to level up as fast and as high as it gets, second kind are after fairly high level but premium is put on getting rich in gold and have best items possible and third kind don't get either, they sort of like to potter about mir lands, they typically stay within range of levels that mir sort of provides balance for, they chat and tame mobs even if that later is considered ineffective but the hard nosed levelers who also don't spend much time chatting... I'd like server that caters a lot to those pple of the third kind or at least doesn't forget about them, leaving mir features for levels under 40 bare because all are just chasing 40+ when the game is considered to start.
I don't want to see cave teleports, better compromise is to make it easy to get at least some kind of basic transport, like horses on Chronicles that every noob that does quest gets it. And other riding animals could be made faster etc. that you can get later on with more effort.