Keep in mind this info is maybe a bit dated now- but here are some thoughts.
The later pistons with 1.2mm top rings are a pain to get rings for.
It was actually more straight forward and not much more money to do T5 pistons (which come complete with pins and rings and incidentally use a 1.5mm top ring just like all sorts of 1980's VW/Audi products with 81mm bore, so getting future replacements is easy). They were about $80 a pop then but I think they're a bit more now. Brian at Amboss Corp is the guy to talk to.
I read about this in your thread, though I was under the impression that it was done for the sake of better ring spacing. At first glance, the pistons that came out of the engine look to be in good shape. Ultimately, the cost difference between replacement rings and replacement piston assemblies may decide the issue.
I'd leave the oil pump alone if you have no specific reason to do otherwise. Do get a waterpump and make sure it has a steel impeller. Replace the t-belt tensioner even if it seems fine.
I guess I'll just clean the existing oil pump up and reuse it. I'm planning on replacing the T-belt and associated parts, along with the water pump. While it's all apart, I might as well do all of the seals too (the idea of reusing any of them after having things stripped down seems terrible).
The rod bending lore is purely related to tuning issues, but while it's apart h beams are cheap insurance. I made ~470whp on stock rods and pistons, but with a big turbo which kept low rpm cylinder pressure and boost spikes low to nonexistent. I made ~540whp on h-beams and T5 pistons with a much smaller turbo. It was a great setup.
Good to know. I talked to Eric (Erik?) at RSI and confirmed that they can still get me the rods. Planning on ordering a set of those and a set of ARP head studs from them later this week. I just need to confirm that this block is good before I pull the trigger.