I hightly doubt your crank is bent...for now.
However, throwing off the balance with a bad flywheel could do that...as well as wreck the seal, etc.
Boonman can get you a used, lightened flywheel for very cheap.
I think, DON'T QUOTE ME, but...he charges like 60 bucks for a used lightened one shipped.
Again, PM him...I'm not 100% sure, he and I worked out a deal...so, ask him.
You ruin a crank/bearings/seal, you're gonna wish you spent just a bit more.
In this case, better safe than sorry most definately applies!!