1995 Nissan Altima My mysterious 95 Nissan

1995 Nissan Altima Automatic

I'm not sure which category to classify this question in, in my opinion it could have anything to do with suspension, to engine performance, but I know very little about cars

a bit about the car's history, and things i've noticed:

i have a 95 nissan altima
when I first noticed a problem with the car, I was at a red light and it began to jar and mist a bit
after I began to pick up speed, which is another issue; i've noticed a lack in it's ability to accelerate properly. Every so 20 mph it picks up, it has a pull to it- I have no other way to describe it
when I am at a stop my car shakes, and idles really bad (to the point where the person in the car next to me could notice)

the transmission has been replaced by the previous owner

once I was in traffic and heard a squealing sound and it began to idle tremendously ; I thought it was going to die

another time I was making a right turn and heard a popping sound
and a few raddelling noises, but these only happened once and I haven't heard any more

also, it would use a lot of power steering fluid, but as of my and the mechanics knowledge that is no longer a problem

the local mechanic who looked at it for me was for certain it was a suspension problem- something to do with the lower right control arm control bushin
which I just replaced- a nearly $300 part that did me little good(no popping sound when I turn )

it still mist, idles, and shakes when I come to a stop, there is no difference in the acceleration
and I'm wondering if maybe all it needs is a tune up, or spark plugs?
maybe something to do with the fuel injector or sensor?

it's driving me crazy, so please give me some advice before I spend $300 on another somewhat unessesary part