1 Lucky Texan

it would be an exceedingly rare failure.

on the older cars, ground connections may need to be refreshed to keep sensors working accurately - disconnect, scrub all surfaces with a wire brush, reconnect, maybe coat with dielectric grease. they are all over the place under the hood - near the pitch stop mount center of firewall, intake manifold, fender, strut towers, etc. but, it seems you know the engine is actually getting hot? when it's overheating, any bubbles coming out?

look in the power steering tank for bubbles while idling - maybe get a helper to whip the wheel back and forth a little.

^^^ good post triple check all ground connections ? look for pinched wires ?

first, keep an eye on fluid level IN THE RADIATOR - don't rely on the overflow level. is the overflow bottle filling up or overflowing? are the fans working? is the car more likely to overheat at a long light or waiting for a train? some folks have found a lot of debris/bugs trapped between the rad and the a/c condenser. is the thermostat OEM-style? it matters;

unless severe enough to foam fluid out of the tank, it won't leak fluid OUT, it sucks air IN. look in the tank while the car is making the noise. On some tanks it's tricky, you have to get your eye right done to the top of the tank. I had to do the o-ring replacement on my 06 WRX last year. noise and 'notchy-feeling' steering.

something they use for diagnostics/reprogramming ?

weird - will the engine stall if you dump the clutch in top gear? what kind of gear oil is in the trans? should be NON-synthetic GL-5 I think (I'm not sure about soobs that old) sure seems like a clutch problem, or a shift linkage issue...????

look in the PS tank for bubbles while idling - you may need to pull the intake snorkel off and have a helper turn the wheel. if you have bubbles (ok, one or 2 every few seconds from splashing is fine) you need to do as said above, stop air from being sucked in. however, if the evidence points to a bad pump, they are known to be very robust parts and you can save some $$ by swapping in a pump from a wreck. car-part.com or maybe LKQ

what shop is this? have you looked at their google/yelp/angies list reviews? anyway, poor driving habits in SF could lead to premature clutch failure - you OR the previous driver could have contributed, but to say you have a bad trans at the same time seems suspect. you don't want to pile problem on top of problem - if this shop can't be trusted - get all the 'pieces' to a better shop.

that seems like a weird combination of failure but....? have you been having any problems lately? maybe jerking/binding when maneuvering in parking lots? all 4 tires identical? I had to have my WRX's trans rebuilt - 2nd gear was destroyed. The tech said 3rd gear is most common, but second happens as well. I have no power mods and this happened at about 70K miles. there was no problem with the clutch and they didn't even see enough wear on it to change it - I was shocked as I drive 95% surface roads. You need a GOOD explanation of what's going on - or a different shop.

seems like the previous battery gave you OK service, what brand is it?

put some thread lock on it???

if you get an entire transmission, be sure the final drive is the same as your rear differential.

I have read of several 5 spds that behave like yours (seems OK when stone-cold, but binds after 10-20 minutes of warm-up) and it almost certainly is the center diff. here , many folks would source a used trans from a wreck - perhaps getting one with fewer miles on it. But some folks do order a new viscous unit and replace it inside the trans. you might dig around at www.opposedforces.com for a part number. seizing brake caliper, u-joints and 'maybe' the carrier bearing could possibly cause similar problems so, make certain they and everything else, are OK before doing any expensive or difficult transmission work!

that car is overdue for a timing belt system service. 105 months OR 105K miles, whichever is first. given that it wasn't driven much, it's possible he saw a little water/oil emulsion in the PCV line or under the oil cap or somewhere.

maybe here; http://www.subaruoutback.org/forums/138-gen-5-2015-present/158858-msrp-invoice-purchase-price-thread.html

I can't add much except, our outback seems VERY susceptible to bad reading if it is LEANING slightly. Uneven surface left-to-right will throw the dipstick reading off a lot. but that doesn't explain a difference after 6 tries. You might pull and wipe the stick, then set a 2 minute timer and re-try. It can seem like an eternity if waiting is all you do - pull the stick, then check air pressure in the tires, washer fluid level, look in the radiator, etc. - THEN check the oil.

trailer harness ?

how old is the trans fluid? It's also the only fluid you must check when idling. make sure it isn't low on fluid. many people have improved old trans performance with 3 drain and fill cycles of new fluid (this get you about 80% new fluid as only around 1/2 the volume can be drained) . Some have gotten better performance with the addition of an additive like Trans-X on the final fill. Helps to freshen seals and cleam gummy deposits that might interfere with valve function. also, old plug wires can sometimes be cracked and will cause misfires on cool/moist mornings until engine heat dries the water. You MAY have 2 problems but, as you say, it could be all transmission-related.

any more difficult to start when cold than warm? there is an engine temp sensor (not the same as the coolant temp gauge in the instrument cluster) that the ECU uses to determine when it should 'choke' the car. (send xtra fuel due to low temperature) I suppose it's also possible something elese is changing with temperature; a vacuum hose leak or ???? any smell of fuel when cold?

how did you change the idle? IACV solenoid is set at factory and should not be altered. or, did you replace the IACV ? when the brake pedal is depressed , 2 'basic' things happen; there is a demand for 'vacuum' by the booster, and, there is a demand for electricity by brake lights. if the car were idling and you turn on the bright headlights...any problem? If the car is in N , any change in behavior? is the check engine light on? any repairs or maintenance done to the car immediately before this began?

They did mention earthquakes. The building codes have been moving targets but seem to be about as comprehensive now as possible. The country has 3 times the architects : general pop ratio as the US !

good idea ^^^^ power steering frequenly makes a whining noise = look for bubbles in the PS fluid tank. do a search. common issue. I've had to replace o-rings on bith my soobs' ps suction hose adapters. check the IACV hose that connects under the intake tubing, maybe it's cracked.

^^^ stiffer but not taller springs are a really good upgrade - since you likely need shocks - do both at once. spring upgrade gets better cornering AND less squat and dive.