they use regular gas, i have an 07 and i was using 93 octane, and i ran into problems with my engine, i was then informed that in all their models(sonata) they recommend using regular, and the ecu is not programmed, to adjust to the different octanes, and it is therefore bad to use high % gas. However it is recommended to use it once in a while to help clean the engine. As far as steering, i believe it is normal, old fashion steering.
For problems you need to look for, where are you buying it from?
For problems you need to look for, where are you buying it from?