Batmud? Ha. Try
retromud instead. They forked off from each other, like...I dunno, fifteen years ago, something about some misconduct on the Batmud side, and have nothing in common now. Retro's fairly populous, and is heavily party oriented. Fighting and casting by trigger are super discouraged, about as far as triggers go is that most tanks have triggers to tell their party when protective spells fail. It's fairly well enforced too. But the players and staff are hugely friendly.
Check out all their races and all their guilds, on that webpage.
There's lots of races but if you ask what the best fit for a given guild is, you can prune it down to like 10-20 or so, and they're pretty much all viable (just don't play a race that's hurt by sunlight as a newbie, because that's pretty crummy...and being able to see in the dark and light both is useful)
There's some people who RP a fair amount but in general there's a low level of it. And...let's see...for guilds, you pick one primary guild, and that primary lets you pick from a list of secondary guilds at level 20+, and that secondary gives you some tertiary guilds to pick from. You can also take a handful of levels from other secondaries or primaries, so your guild choice is likely to be fairly unique (I've got a satyr who's a mage geomancer and also going to take some slinger, some bard, some telemancer...)
And while walking around new areas in cities (not overworld) gives you free experience early on, it won't take long at all before you're beating up various sentients. So no, you're not beating up on sparrows for hours.
Um...Essentially no player killing (though there's occasional arena-style wars for fun), and while a tank or blasterish sort of person can solo alright, past level 15 or so you'll definately want a party of 2 or more, as many as 8, when you can find 'em. Oh yeah and levels go up to 100.
While it DOES have the 'donate for stuff!' thing that more annoying muds have, you can't turn your donation straight into gold, can't use it for XP, you mostly use it for 'wishes' which are largely inane things like 'yay, now I can fly without a spell or specialized equipment, now I can fill out two secondary guilds, and other things that won't even help you out until your character is much higher level anyway'. So it really isn't a huge advantage at all.
You really have a lot of choice between high-stress and low-stress characters, too. In general only tanks can lead parties, so it's a good idea to play one at first, and they're good for soloing, but can be a bit dangerous to play as at higher levels since you're the one leading the party. Healers (biomancers mostly, but also templars, cultists, druids...) have a very stressful life and are great to play if you're really on the ball. Blasters (tons of classes) are a bit more relaxed since they're not really 'driving', I mean they have to know what's going on, can figure out the best spells against a given enemy and (of course) don't want to cast a spell that'll get reflected at them, but they're fun for more casual stuff. Abjurers cast tons of protection spells and if you're very lazy and casual you'll like them a lot, since at low levels you cast most of your stuff outside of combat! Tons of classes are multi-role and of course you get much more complex as you go higher, but there's something for everyone.