[Too much rust?]

I had a similar rust problem and was worried about the frame integrity.  NY State rust belt car.

 

Found this product online--  https://www.theruststore.com/Rust-Converter-Gallon-P40C10.aspx

 

Used a wire brush to remove some of the superficial rust and applied the product as per directions.

 

After drying, noticed a few areas that needed a second coat.

 

I'm happy with the result, and feel relieved that the rust is arrested.  I didn't feel the need to top coat with POR-15, but if you have the time that would be an awesome way to finish the job.

[a/c shuts off, then works if I start the car again]

The pressures look good.

 

Use a feeler gauge and measure the clutch/cover distance.  Too tight and the clutch may not release/cycle.  Too wide and the clutch stops engaging as you drive.

[a/c shuts off, then works if I start the car again]

"how much refrigerant did you put in the system?"

 

----what's the reading on the low pressure side?

[Discount Subaru Parts]

Lately I've been using www.parts.com for my Forester and other cars.

 

 

$13.07 plus 10.99 and 2.00 shipping/handling for part 809218370.

 

 

They stock parts for most Makes and Models.

[replace battery and car won't start?]

Didn't see grossgary's update.  Ok, so it was due to a blown fuse.

[2010 outback overheating]

First off, only use a OEM thermostat.

 

If it is the head gaskets, then you can check the decks for warpage using a machinist's straight edge.  If out of spec ( >0.0025") , then a machine shop will have to machine the heads flat.

 

From your description of things, overheating and 'puking' coolant out of the overflow tank points to head gasket failure.

[2010 outback overheating]

Ever had the engine overheat before this happened?  If so, the heads could have warped causing a premature head gasket failure.

 

Was any work done on the head gaskets before?