Not true: I have a Fighter/Mage/Valkyrie/Sorcerer, with a fifth "slot" being accessible obviously for the 3rd tier.
It IS the (inferior to CE) MMXII game, though, might want to keep that in mind.
It comes with tooltips on most menu's and stats, so that helps. Spells now show appropriate damage, AoE & duration info.
Weapon, Magic & Repair skills increase on their own.
Armour skills actually have benefit, i.e. armour provides loads more protection with skill points.
It still features the crappy durability, so anything non-plate/scale with certain weapons is virtually unplayable due to paper gear. Repair kits are more common, though. (But not common enough by a mile.)
Scout/Mystic Vision "works", but offsets all info on the map to the right, making it rather hard to read.
So far, I didn't have a single bug.
Oh, yeah, the "Bash" skill is the way to go: level it ASAP & never touch the thief skills.