Sorry, real confused.

[freeforeall]

I am thinking about buying (well, financing) an RSX. I have many questions. Trims I'm interested in are RSX and RSX-Premium (I am in Canada). I am not int'd in S-type as they have lower fuel economy and require premium fuel. As well, the listed engine torque ratings are very close and I thought torque was a big factor in how peppy a car is for normal use (normal use for me constitutes daily city driving and maybe 10 8hr HWY trips per year).

Questions:

1. Is there a noticeable performance/comfort difference b/w 15 and 16" wheels?
2. Is there a noticeable performance difference b/w "sport tuned" and "dual-stage" intake manifolds (regular and s-type respectively).
3. RSX has no ABS (RSX-premium does). Can dealer or garage add that technology as aftermarket modification?
4. S-type specs list "sport tuned suspension." Is this simply tighter springs...can AFFORDABLE aftermarket accessories make regular RSX equivalent to or better than stock RSX-S suspension?
5. Would HID lamps improve night driving (pref'd driving time). Are halogens/good foglights just as good as HID?
6. Does Acura plan to add curtain airbags to future models (maybe no one knows).
7. Can someone recommend a good link or book that teaches what things like aftermarket headers, different exhausts, air intakes, etc do (ie how they work, how much you can improve performance...)
8. Do things mentioned above (in 7) SIGNIFICANTLY enhance driving for normal user (I will not go to track or participate in street race)...ie is car noise/performance improved enough for non-mechanic to notice the difference.
9. Do things mentioned in 7 change fuel economy?
10. Do things mentioned in 7 ruin warranty coverage (I did read a post on this at this site but didn't understand fully...guess with so much else to read, I'm looking for quick/dirty answer)?
11. Are lumbar support & tilt/height adusting seat worth upgrading to RSX-premium...big comfort difference?...can driver's seat be upgraded aftermarket?
12. For long drives, is cloth seating more comfortable (better breathing) than leather?
13. Can cruise control be affordably added aftermarket?

$3000 CAD (2230 USD) is difference b/w RSX and RSX-premium. Extra $ gets sunroof (not important to me:NITM), ABS (very important:VI), better stereo (NITM), 16" wheels (?), cruise control (VI; less tickets), & leather seats w/ height/tilt adjustment and lumbar support (?).

Should I be considering another car...wants are good acceleration, very good handling, safety, gas mileage and fuel type, comfort and reliability. Nissan Spec-V and SE-R seem good but except for 4-door convenience, don't appeal to me.

Sorry this is so LONG, even answering 1 part would be helpful