ronemus

The dust shield is only held on by 3 bolts, so it's easy to remove if it's in the way. I just did mine, but I stripped off the shield before I used the puller.

That style works very well, but there are 2 sizes: large (for Pitman arm) and small (for tie rod end). Be sure to get the right one for the job at hand (or have both in your toolbox).

I once had the same symptoms from a bad airflow sensor, and another time it was the pedal position sensor. There are lots of possibilities for those symptoms. It will run without the O2 sensor, but it does so in limp home mode which would be as you describe - I would start with a new O2 sensor. Rock Auto sells Denso Front O2 Sensor which is GTG. How is fuel mileage? If the A/F ratio is off the mileage will suffer.

Look at the clearance between the tire and the front spring perch - in all the Subarus I've owned there hasn't been much. I think you'll find that the small increase you could get would have no real impact.

Use Speed Bleeders - just open, stomp as many times as necessary, then close. I've used them on all my cars for over 20 years and they've worked flawlessly. Easy and inexpensive.

Replacement upholstery for Subaru Seats has been discussed on the Subaru Outback Forums - try searching over there; there are several aftermarket sources. Alternatively, you could replace the seats with units from a pick-n-pull yard. The cost and time involved are probably similar for either option.

I haven't owned the Gen4, but had a Gen3 and have a Gen5; on both of those that much increase in diameter would have rubbed the underside of the spring perches (there was less than 1/2" clearance with stock diameter). If a smaller-diameter wheel will clear the brake calipers, you may be able to run the higher profile on them.

boat payment

You'd do better with links using pillow balls, for example Whiteline's.

It can be either the canister or the valve. It's easy to replace both and they're not very expensive, just messy because they're located behind the passenger-side rear tire underneath the car and road filth accumulates on them.

Did you bump the shifter into the manual gate? Unless you were on a steep downhill grade with a tailwind, you shouldn't hit the rev limiter in top gear.

I've done it by popping the camshaft out; they can then be easily removed with needle-nose pliers. It gets a bit fiddly keeping track of which shim goes where and what the clearance was to calculate the new shim thickness, but it avoids buying an expensive tool. I've only ever done this once on any given vehicle and I keep mine 12+ years, so I couldn't justify the price tag on the tool.

Overfilling oil may have overloaded your catalyst of damaged your oxygen sensor. Has your fuel mileage changed? If engine oil was overfilled, you can probably find evidence of it in the vent lines and airbox.

Be sure to use the full kit (belt, idlers, and water pump), not just the belt. I thought I'd get away with just the belt on my '02 at 60k and do the full kit at 120k - WRONG! It failed 400 miles from home and put me at the mercy of a mechanic the locals said was good - WRONG! It was expensive, frustrating, and left a whole series of Easter eggs for me to find and repair. Really, who breaks the head off a bolt and just epoxies it in place? There's no harm in shortening the maintenance interval if you are concerned - much easier than totally re-engineering the engine and controls.

OEM cats are required to last for 100k miles/10 years, but aftermarket cats are only requires to last 35k miles/4 years (not well publicized facts). I tried a couple of aftermarket cats and guess what - they lasted <40k miles! The aftermarket cats are not any sort of good deal - stick with OEM (especially if you're paying a mechanic for installation).