while cranking, feed-in some starting fluid, unlit propane or maybe brake cleaner into the intake, if it fires, you have a fueling problem. If not, likely electrical.
Pull the inlet line to the filter and stick it in a bottle. The try to turn the car over for a second. There should be fuel in the bottle. The filter is on the firewall next to the wiper motor.
If you want to use that WRX as a donor, you need at least a first gen (1990 - 1994) Legacy. The Loyale is not compatible and the EJ20T will tear it in half like Jesse Ventura with a phone book.
GD
I’ve run front axles 50,000 miles while clicking with open boots. Not a big deal with oem axles if they only see clean roads. Sand gravel etc is bad mojo. I could do that in Atlanta and Maryland with consistent roads, but not where I live now.