Honestly, your axle will ALWAYS be a bit off one side or the other depending how much weight you or don't have in your Jeep. It's the nature of the beast when it comes to track bars and really, I wouldn't give it much thought, especially in the rear and if you're not having any rubbing issues.
Technically speaking, you never really need to pay someone to do an alignment and more times than not, they just take your money to make a print out of what you already have set being that UNLESS you have adjustable components, there isn't a whole lot they can do.
That said, If you're still running factory arms, no, you will not need an alignment. IF you are running adjustable control arms AND have adjusted them out, YES, you "may" need to make a correction for that.
Last but not least, the bump steer you're feeling will NOT be caused by your control arms. If anything, what you are feeling is a symptom of your track bar and drag link sitting at a steeper angle. A relocation bracket and drag link flip will help flatten them out and improve steering feel.
The factory rear sway bar is on the lighter side but I kind of feel like it gets the job done or well enough. I kind of think that what you're feeling in the rear is just your shocks being on the soft side, which is typically the case with stock shocks and even higher performance ones.
