Sometimes the harmonic balancers seperate from the rubber. If they do they wobble and need to be replaced.
Sometimes the bolt for the alternator works loose and it walks out rubbing on things
Make sure there are no vacuum leaks. The throttle cable may need to be adjusted properly.
The stock oil pressure sending units suck and fail often.
As for the brakes you could have a line leak. Does the pedal immediately sink to the floor?