really? hmm, i guess low speed and respectable Atk and Def don't always mean good Curse user :/ but now that i think about it, Slowking would better, i suppose, since it'd boost his lower statsbad idea, Curse Slowbro sucks. At least use Slowking, it sucks less.
I use the same set, but with CM over Slack Off and Lefties over Lum. I find that Regenerator + Lefties negates the need for an instant recovery move, though my set suffers from Toxic much more than yours does. That's really the only status Slowbro hates though. That, and sleep I guess though almost everything hates being asleep.I use a Slowbro set like this:
Slowbro @ Lum Berry
Bold, Regenerator
252 Def/252 Sp A/4 Sp D
Fire Blast
Ice Beam
Thunder Wave
Slack Off
It's useful for getting surprise KOs, and as well as spreading around paralysis. Lum Berry to stop status, and give you a turn to paralyse opponents. Able to OHKO Ferrothorn, as well as outspeed it if it tries to switch in. Bulky enough to take most Outrages (haven't been able to play for a while though, so not sure how much exactly, nor from whom), and then either KO with Ice Beam, or at least severley dent them. Great tank overall.