Some newb tech help/advice please

Hello all. I just bought a 2006 base Tacoma 4X4 with the 2.7L with a 5sp. trans and only 17,900 miles on the odo (also my first Toyota). I changed the oil, oil filter, and air filter when I brought it home yesterday with Mobile 1 (~5.5 quarts) and a Toyota oil filter. I plan to replace the trans fluid and both differentials' fluid this weekend, as well as clean the throttle body, IASC valve, and MAF sensor. Any recommendations for any good synthetic fluids for the trans and diffs would be awesomely appreciated, as well as the required weights. I also filled 'er up with Shell 89 octane E10 (there's no avoiding ~10% ethanol around here).

There are a few things I've been noticing and I can't figure out if they're normal. This newbie could really use some advice

1) At cold start, the engine revs to ~2000 rpms and holds there for about 5-7 seconds. There's a "blowoff" sound like lightly compressed air being released, then the idle steadily lowers to ~1100 until it warms up a little and drops to ~800 rpms after a minute or so. Is this normal? I also get a rev-hang every once in a while when shifting from 4th to 5th gear, which everyone seems to point to the IASC valve. I'll probably end up cleaning that this weekend too.

2) Apparently, the valvetrain and the EVAP purge valve, combined with the injectors, produce fairly loud tapping at idle. Sounds like a quiet diesel engine from the inside of the truck to me. This is separate from the exhaust-hitting-manifold sound I hear under load. Is the 2.7L engine excessively ticky, or is it mainly the 6 cylinder engines that make the most noise?

3) The shifter visibly vibrates at idle, clutch in or out doesn't matter. I can't make it stop by holding it. Do others experience this?

4) I have a software program on my laptop left over from my Volkswagen days which is also able to read OBDII on both my wife's Honda and apparently the Tacoma. I can monitor and log most all sensors in live time, read and clear trouble codes, and get engine management information. I checked the absolute throttle body position tonight and it read 46% with the engine off (normal?). My VW used to read ~7% with the engine off. If I press the gas pedal it will rise to a max of 67% and the throttle solenoid whistle/hums like it should. But then when I release the pedal, the solenoid continues to hum indefinitely, like the valve can't quite get back into resting position. I'm thinking that the throttle body needs cleaning pretty badly, or else it needs to be recalibrated, which I hope can be done by unplugging the battery. Any ideas?

5) My long term fuel trims are 3.9%, which means I'm running a little lean and the injectors are staying open slightly longer to compensate. What could be causing this? My wife's Honda never deviates from +/- 0.6%. This may get better if I clean the throttle body and IASC, but I'm not sure. It may also be a MAF issue, or even the injectors being clogged.

6) The manual trans is notchy shifting from 1st to 2nd gear. It's borderline grinding (not quite though) when it's <25*F outside, at least until it gets warm. I am planning to change the fluid to a good synthetic (Schaeffer's or Redline), so it may go away after this. I just wanted to know if this is fairly normal for those who are still on the factory gear oil? Also at idle in neutral, the trans seems to make a quiet grumble. Also normal?

7) I read plenty about this on these forums, but I'll bring it up anyway. The driver's side front axle is pretty loose where it attaches into the front differential. It doesn't make any clunking or grinding sounds and there's no leakage, but I can move it a few millimeters in/out AND up/down. I've read that it's a needle bearing issue, but since I'm not planning to do any real offroading, I was wondering if its something that I can let go for a little while, at least until I hit 30000 or 40000 miles? I'd like to be able to use the 4WD when I need it in the meantime without destroying the diff. I don't want to spend the time or money on fixing it until I buy a house and have a garage to work in (enclosed carports suck for any major work ).

Sorry for such a long post. These were just issues that are touched on in these forums, but I couldn't find any definite answers to. Thanks so much, this forum is a treasure trove of info!!!