You got the car for a decent price.
Mechanically the RX is pretty much bulletproof.
Regarding the wheels you may find a decent set on Ebay(Lexus originals) that are cheaper than getting yours refurbed. Corrosion with the original Lex alloys has always been a problem, more so on the IS model.
Regarding servicing, look around for a good independant garage that has a good reputation they are "Toyota" after all ,so pretty easy to service with no major problems.
Good luck with and enjoy the car and these forums.
Welcome to LOC
Terry