You need to take polymorph for stealth, if I'm not mistaken.
Aero isn't that good as combo anymore, because aero goes against magical armor and rogue against normal. And only Chloroform helps vs magical armor.
I would never take Aero on a Rogue for the Air damage. But I might for all the utility skills, like Teleport, Netherswap, Uncanny Dodge and others too.
