[V8] First time lister with many questions

[gabe holmes]

First off, I bought this car with a bad transmission (so didn't really have 
a chance to drive it first; engine sounded great and only had 86k mi)  
anyways, i had a transmission shop put in a rebuilt tranny i got from a 
wrecked V8(rebuilt in 1999).  After the install the car smoked perfusely 
(especially going up hills), figured they over filled the case since they 
didn't know how to check fluid level.  I lived with it for awhile, then the 
car started have trouble shifting from third, had to play with it manually 
to get it to kick over (seemed fine if i punched it).  At the same time this 
was happening had a problem with holding idle after starting up hot.  So 
took it into an Audi shop for diagnosis, found the O2 sensor was dead (so 
they unhooked it for a temp fix until i could get one installed), and that 
the tranny fluid was a little low .  THen the next problem arose; when 
pulling up to stop lights applying the brake, and in reverse, the car wants 
to lunge forward (backward) as if i am pressing the gas at the same time as 
the brake, and it kills the engine.  Also the car started going into 'limp 
home mode' a couple of times (turned car off to reset).  Fed up, i took it 
back to the tranny shop figuring they hooked something up wrong (these guys 
aren't audi guys, but only people that would install my used tranny), and 
also wanted to check for leaks. They halfway unhooked the tranny and dropped 
it enough to examine the tranny, found no leaks but an accumulation of 
tranny oil sitting in one of the heat sheild (probably from when they 
overfilled it, also explains why it was more apparent when going up hills).  
However, when i got it back it ran horribly (was having no running problems 
after the O2 sensor quick fix).  So i took it back to them figured when they 
dropped the tranny they disconected some vacuumn lines (also broke nipple on 
my H20 resevior).  I'm wondering if there is anything other than vacuumn 
lines the could have ruined by improperly lowering the car. to add to the 
mounting problems i also am experiencing the troubles of the bose stereo. 
The car had an aftermarket cd player w/out face so i replaced it with 
another unit.  During the install i saw that there was some sort of 
adjustable (power to each channel) do-dad unit that was spliced into the 
speaker wire; assuming this is to regulate the power that is sent to the 
amps.  This do-dad, however, doesn't work properly, i am getting intermitent 
power to the different speakers.  Also i am getting whining noises from my 
front speakers, probably rears as well. Most certain its the do-dad.  When 
they system works it sound great, want to keep this setup just fix it.  OH 
yeah i just remembered, my steering is also fouled up.  I think the steering 
rack needs to be replaced.  When i turn the wheel to the left it takes about 
an eighth of aturn to get response, hoping that something is just out of 
adjustment.

So my Questions;
1) Is there any relation to the tranny having difficulty shifting out of 
third and any of the aforementioned problems?
2) Does anyone know what causes the car to try to lunge at low speeds when 
brake is depressed? Idle is fine when i put it in nuetral so i figure it is 
probably related to the tranny.
3) Any suggestions on what these tranny guys messed up by lowering the 
tranny down, so i can tell them how to fix and start driving my car agian?
4) Any suggestions on my stereo perils?
5) Do i need a new steering rack or is this a problem that can be fixed w/an 
adjustment?

Sorry for such the long post, but trying to get all the issues out in one 
fail swoop.  I love this car when it is running properly, eventhough its a 
thirsty beast.

Thanks everybody