tires + auto-trans questions, audispotting

[rochow@pixelmagic.com]

1. After being reminded by the "compared with a 5k automatic,
it's bulletproof" sort of comments, I'm wondering about
the replacement of ATF and diff. oil (and AT filter cleaning?)
on my '84 5kS. I've owned the car for a little more than a
year and maybe 4000 miles now. While there may be some
systems that one wouldn't want to open up to change fluids
until it's really necessary, there is no argument against
having both diff and AT drained and refilled, is there?
How useful is ATF filter cleaning?
The car, BTW, was owned by a care- and clueless
moron before me; the transmission engages quickly
(and harshly? Compared to my Caprices, anyway) 
most of the time, though it's sometimes slow to switch
to 3rd after letting off the accel. after accellerating
hard in 2nd.

2. Tires: While Hakkas seem to be the item of choice,
I'm looking for an alternative due to price and, moreso, 
availability. I'd like something that performs rather 
wonderful in snow, without being utterly ridiculous 
(or fast-wearing) in normal dry or plain wet weather. 
The car in question is a 4070 lb RWD Caprice; it's 
old Yoko all-season tires get stuck on an ice cube in 
my <5%-inclined driveway.
Any recommendations? Thank you.
(What about size, BTW? It normally has between 
205/75 and 225/70 tires (7.5x15 wheels), should one get
narrower snow tires?)

3. There's an S4/S6 (green?) often parked in downtown Hudson,
MA, and a dark (black?) S4/S6 at Brickstone Square in Andover.
Listers?

-gbr