It sounds like the symptoms we had with our 97 OB when the alternator way on its way to dying: strange electrical behavior, then full recovery. Other things that happened to us in addition to the "engine trying to start" symptom was the needles (speedo, tach) dropped to zero, then recovered.
Getting a new battery "cured" it for a short while until the new battery discharged due to faulty alternator. I also believe there was a recall on the alternators for certain model year Legacies, but I don't recall the specifics.
Hope this helps.
An aside for those who may have known me as "CincyBuckeye" on the former USMB: I've moved to Durham NC but the old board software wouldn't let me change my name. I moved so that I could be closer to the proposed East Coast Subaru gathering that was planned for the Outer Banks (and also because this is where my residency program is).