In an
interactive dungeon crawl (e.g., RttToEE) - or just one where foes (or heroes) occasionally retreat and could be encountered again later -, its duration is quite handy. Can't beat something (say, it has energy resistance or damage reduction) but have some days to spare? Just nail the critter with
bestow curse as often as you can, retreat, prepare other spells, and come back.
Heh. Anyway, I have to admit that I've always seen
bestow curse as more of a cleric spell anyway (which it probably is, too, given that it's lower level for them) and thus, didn't really compare it to other 4th-level wizard spells.
I still wouldn't reduce
bestow curse to 1st level... Reducing it by one level (Clr 2, Wiz 3) sounds good enough to me, though.
At that level, we have
hold person (also Clr 2, Wiz 3) - which is a spell with a nastier effect (helplessness) and a much greater range (Medium), but also much less flexibility (only one possible effect, and only usable on size M or smaller Humanoids; it's also mind-affecting, but since few Humanoids are immune to that, that's not an issue in most cases) and duration (only 1 round/level).
Sounds about right IMNSHO.
As for
mark of justice: Good point about the casting time!

Considering that, it might be better to place it at the same level as
bestow curse - or 1 above that, but certainly not 2.