Age ago, my longest session was over 22 days XP h24. This is impossible now without been caugh by GM.
Some time (without using any "3rd" program), they have suspend me.
I was pling 5 alts & i was doing a 3-5 mins pull with a high level char.
For more than 2 time, a GM come where my alts was (AFK but not with the <AFK> tag), he speak in say and as i do not reply (in 22 secs), he suspended for 7 days the alts AND the puller.
I did not see his message because i was playing the puller.
They can suspend you too if you let 2 chars online with 1 cleric merc and 1 tank merc.
So i recommand you to play with the "assistance" of MQ2, but not to AFK play. It is probably possible to AFK play, you will take the risk to get a week of suspend, but not Bane.
Now, it is almost impossible to play Everquest without boxing yourself 3-6 chars.