yes absolutely mq2 and by extension redguide's Very Vanilla works on "live" everquest. It works on all non-truebox servers - so wether you're on cazic-thule, or bristlebane, or even the tlp Rizlona - as long as it isn't truebox, it works!
we also have a test server and an emu build version.
re: the char models - some folks like the "old" models, and some even use the stick figures (both of these things you can use without running macroquest just from everquest itself)
Kissassist and other macros like RGMercs, or even something simple like pokscribe are just "scripts" that perform actions using information they can get from macroquest itself. You can have something that does full combat automation, or something simple like moving around gear, organizing your bank, looting mobs, summoning something etc.
there are also plugins which are compiled additions to macroquest2 - things like mq2autoloot or mq2status which have specific things they each do.
in the next major overhaul for macroquest, colloquially called "MQNext" there is also an mq2lua plugin which allows .lua concurrent lua scripts to run. this is significant, because macroquest2 only allows 1 macro at a time - but this is getting into more advanced than "day 1" kinda stuff.