Occasional cussing is fine; directed abuse is not
I don't see it as a huge problem currently. But that's just my feeling, so let's break this down a bit first before drawing any conclusions:
I'm a person who finds posts with bad language/profanity unprofessional...
I don't disagree with that sentiment; but:
Super User is a question and answer site for computer enthusiasts and power users.1
While there are a lot of professionals using the site, it's not aimed at exclusively (or even primarily) at professionals. From your next sentence, you may instead be suggesting that it hurts the professional image of SU (and/or SE) itself.
I'm not sure that the presence of swearing itself tarnishes the whole site- the Q/A format is pretty clear; off-topic and incorrect information gets removed quickly; good answers in theory rise to the top. These are good, important ways to promote the site; swearing doesn't diminish the image as much as lack of clarity / prevalence of off-topic etc content.
However, that does bring us back to the last part of your first sentence:
Ah, this is a trickier one. Everyone is entitled to their views; and it's good that you don't permit your views to delete any post with profanity. If you (personally) don't want to see it - and I'm sure there are others who feel the same - perhaps there might be call for a userscript that filters it out. Doubtless there are browser extensions, but this feels like something StackApps might be a good fit for.
Of course, if it is deliberately, provokingly offensive; go ahead and edit or flag!
The short answer is: it depends on the context. If someone is directing abuse at someone- that's not okay and it should be removed. If someone curses a particularly egregious design flaw- let it be, it's just them expressing frustration at
n hours of their life being wasted as a result.
Auto flagging? I'm going to stand on firmer ground here and say no way, in my view, if for no other reason than false positives. But if you want further reasons- people deliberately circumventing the 'swear filter' (okay, swear autoflagger, but tradition forums have the same issue).
And another thing
I'm going to throw in that you don't need to swear, cuss or be profane to direct abuse or be offensive. For an illustration, I'll hand over to 'a bit of' the work of Mssrs Fry and Laurie, in script form.
1 I'm sure you don't need me to cite this. grin