1988 5000S Quattro New Subscriber

["Christopher J. Ritchie" <cjr1@gte.net>]

I am the new owner of a 1988 5000S Quattro; a new subscriber to this list;
and, a relatively recent Internet researcher.  The car is in good shape
with ~ 90K miles (the odometer has been replaced).  This list is a real
help and service to people like me.  

Queries:

1.  Any recommendations for a mechanic or dealer in the Boston area?  How
about the New York City area? 

2.  Any peculiar preventative maintenance tips for this car?  What about
the timing belt?  Is this engine a non-interference type?  That is, when
the belt fails, do the valves come into contact with the pistons?  I do not
know the car's previous maintenance history.  

3.  Is the factory service manual (Bentley?) worth the money (~ $94 from
amazon.com)?  I am a more than competent "shade tree" mechanic.

4.  The horn will not sound and the turn signals will not cancel unless the
steering wheel is pushed in.  I assume this is not a defect, but is a
feature.  How can I get the steering wheel to stay in the pushed in
position?

5.  What does "UFO", "Urq", and "BTDT" mean?

6.  Any recommendations on other Internet web sites to visit?

7.  The car seems sensitive to cross winds at highway speeds.  Is this
normal?

8.  I usually get a noise from the engine at start up that sounds like a
noisy lifter.  Not always, but usually, especially if the weather is cold. 
Is this the noise I am hearing?  Are the lifters hydraulic?  Is this
typical?  Is it a matter for concern?  If so, is it easily fixable?

9.  How do you set the stations on the radio?  The radio appears to be OEM.

10.  The radio display for the station setting is very dim.  Is this
normal?  If not, is it easily fixable?

11.  The air conditioner does not work.  I realize that a fix cannot be
diagnosed without seeing the car and testing, but does any one have any
advice on this system?  Is it straightforward, or are there any Audi
specific anomalies?

12.  The "Check Brakes" light and bell goes on sometimes after driving a
bit and using the brakes.  The brakes seem to work fine.  The car has the
ABS option.  It appears this warning is triggered by low fluid in the power
steering/power brake system reservoir?  I slightly overfilled this
reservoir to cut down on the warnings.  The manual states to check the
fluid level when the engine is running.  I did.  When the engine is
running, the level dips below the "Min" mark.  When the engine is not
running, the level exceeds the "Max" mark.  (Which is why I only slightly
overfilled it.  I did not want it spilling out when I shut the engine
down.)  I realize that this condition is probably a problem and needs to be
fixed.  Any advice?  Where does the fluid go when the engine is running? 
If it comes back when the engine is shut off, I assume there is not a leak
in the system.  But where fluid cannot compress, where is it going to come
back from?  Finally, is this dangerous?

Thanks for all your anticipated help.