Recent '03 1.8T Purchase & First Manual

I've recently become the owner of a '03 1.8T with about 68K miles on it.

This being my first "personal" car, as well as first manual...and first turbocharged car I've got a few questions. I apologize in advance for the newbie questions.

1) Getting Started

Prior to this, all my manual experience was in a grossly underpowered Ford Explorer with a very forgiving clutch. So...yeah, I've stalled this one a few times.

I've been taught to try to go for a feel on the clutch pedal to know when to gas up, and to "hear" the engine to know when to ease off the clutch. For the Jetta, it seems gassing to try to keep the RPM constant ~1K is a pretty good until the clutch is out all the way.

2) Shifting

Any specifics on shifting?

The car I learned on felt best upshifting between 2500 and 3500 rpm.

With the Jetta, at that point, I start to REALLY feel the engine kick in strong and find myself upshifting at 2000 rpm to avoid sounding like a maniac in local traffic.

3) Highway

I've put about 700 highway miles on it. Here's where I'm really glad I bought this baby.
But since my previous cars could only drive comfortably at <80mph, I was wondering what I should watch out for in a car that cruises Interstates at 85mph, and occasionally dashes up to the 90-100 range.
As far as RPMs, I behave...I always keep it under 3500.

Do I need to change oil more frequently or anything...I know next to nothing about cars, but I assume the higher speeds means higher temps. Any other issues I should look out for?

4) Fuel

The previous owner's manual was smudged at this point.

I know high performance engines tend to run on premium fuel. Being a turbocharged engine, i figure it would need something above regular, so I've been putting super...the octane number seemed to be in the 80's...the second digit is what I couldn't make out. Am I treating it right?

Side Note: Mileage seems awesome...230 miles took less than half a tank. Coming from a fuel guzzling SUV, this was absolutely amazing...I used to run it near empty doing the same trip.

5) Shocks/Suspension

No real issue yet, but over bumpy roads, I hear the shocks(or is it suspension) squeaking. I mean like motel bedsprings squeaky. Is that normal or should I get it looked at.

I've purchased this car in preparation for a long 1500mile excursion, so I'm looking to get it running real nice before I set off. Any experienced opinions and tips would be really appreciated. Thanks.

VW reccomends oil change every 5k. I would NEVER go more than 3000 especially in a turbo car. I would reccomend synthetic oil but you can get away with regular 5w30.

Use premium 91/92 octane only unless you like check engine lights and rough starts with misfires.

As the suspension goes you most likey need new sway bar bushings, its acommon issue with vw's