my 1996 Chrysler sebring convertible is having transmission problems, help ?

i recently bought a 1996 Chrysler sebring convertible with 106,940 thousand miles on it. it runs very good & shows that the previous owner/s took very good care of it.

The only bad thing ive came to realize is that the tranny is acting alittle weird. first of all, if your familiar with chryslers, or have noticed any drive by in your days, you know what im talking about when i say the "chysler noise", its like that "bzzzzz-zz--tck", that like, 95% of them do. thats the tranny. so the problem is, when im coming to a stop, from any speed, once im very close to full stop, maybe 4 mph, itl make the noise, as it should, BUT, at that point, it slams back into 1st gear. sometimes harder than others, but the jerk is very noticable, and is at EVERY stop. any idea what this could be ? before i go to a mechanic and i get told i have to pay $7589897.

Also, today, i was driving, its nowy out, but i doubt thatd have anything to do with it. but it did its usual slam/jerk, then as i went to take off, i accelerated alittle, let off because the guy in front of me must not have had a brain, then as i went to accelerate again, i was in nuetral, i just revved, then after 2 seconds or so it slmmed into drive. this was only one incedent, but it only takes one, ya know ? any ideas ?

as for driving, its shifts very very very nice, you can barely feel it shift, this is why im so confused about whats going on. im usually good with cars, but this has me like, ???? . any ideas ? id really appreciate the help.

On a side note, i think my alternator may be going ? or possibly faulty ground wires ? my gas gauge reads gas levels correctly, but it will constistantly fluctuate, & the little gas light ewill go on and off, also my E-Brake light is on always, even though my brake isnt, if im sitting in park, idling, with my headlights on (at night) its have a PERFECT idle, and every couple minutes, my interior lights ( dash/cluster, radio, ac contols) will all dim & re-brighten, along with an rpm pulse. what got me curious about this, is last night driving, i stalled out, which really had me frazzled.

I know i have a good car here, chrysler are notorious for bein crap, but i believe i picked a good one here, so if you have any ideas, comments, help, anything, please feel free to answer.

THANKS