Sometimes solo ranking is a must.

Going LOOK AT ME, I'M GREAT AND DID IT FOUR TIMES AND YOU PROBABLY ARE RETARDED IF YOU CAN'T DUPLICATE MY RESULTS without giving any concrete results is all well and good (and I have a rough idea exactly what you did to get these results including the area(s) in question despite being explore-retarded).

But it doesn't help without any actual advice.

Here's some REAL advice: if you want to tool around with mage solo ranking pre-30, go find the Planar Sanctum that got put in recently. It's right in the helpfile for it literally screaming 'solo rank me as a mage lol' and examining the mechanics of the area proves it. Get your preferred combination of HP, spell saves, AC and hit/dam and you're set. Don't even need as much hit/dam as your average warrior and finding the damn place is a decent project in and of itself when there is no one to group with, though if you start from the wrong direction you'll die a time or two in the teens without a teleport/recall potion.

Not only that but if you DO get attacked there, melee types will have it more difficult than normal trying to kill you. Other mages will not.