Ford Repair: 1993 ford explorer problems, wheel car, rear tires

Question
Hi..I recently bought a used 93 ford explorer. It gas so many problems I don't know where to start. I'll ask about my main concerns after I tell you the recent fixes. Replaced missing left front bushing. Replaced leaking brake line. Replaced all four tires. Replaced front brakes (couldn't get rotors off rear tires to replace those..brother in law says are rusted on. He tried to bang them off for an hour before giving up). Now the car wobbles back and forth like its gonna tip over whenever I go over a curb or speed bump. Scary! There is a little play in the steering wheel. Car vibrations and shaking is kinda bad..can feel it shaking my legs n body through the seat. Also, rpms keep going up when I accelerate. I have to take my foot off the gas to let them drop down before I accelerate again. Any ideas? Thanks!

Answer
Stefanie, first I think the reason for the vibration is might need to change the rear rotors.  Use a torch to get them loose, this will work, trust me!  As for your last comment, check the transmission, it seems that it is slipping and not getting into the proper gear.