Loss of power, hard starting and short run duration sound like clogged fuel filter, or cracked/broken fuel line admitting air. It's not uncommon as things age, for rubber fuel lines to break down inside allowing chunks of rubber to clog filters or just plain collapse internally and stop fuel flow.
What is the HEVI pump you refer to?
Exactly what oil line did they replace the o-ring on?
Did it have engine oil pressure on your drive home.
Power steering lines should have no bearing on engine power or starting issues.