Hey guys, I have the same setup. I've had them on about 6 months now...I can confirm that Roush recommends stock setup. I changed nothing else either and my alignment is good with no abnormal tire wear. I have been watching this like a hawk too, due to all the reading I did on the subject pre-install. Mine was more of a cosmetic mod, not performance. I did notice less nose dive on braking and a bit sharper turn in on corners, however so that's a plus.
DISCLAIMER: Every car is an individual and where I didn't need alignment, you might. I've heard so much back and forth "you do need shocks/struts" or you don't, I decided to trial and error it myself. So far, so good. I have befores and afters, but they are crap cell photos :/
'11 5.0 SG 6MT Brembo 3.73 Borla S-Type Catback