"...I've never even seen one (a shoot that is ),& am curious..." You owe it to yourself to go to any pin shoot you can. I can't think of any shooting game that's anywhere near as much fun.
"...Just how tough are the pins? I'd not like to break them..." Pins are wood covered with thick plastic. They'll take multiple hits from cast .45's before they get too much lead in them that can cause riccochets and become too heavy. Then they become safe outdoor firewood. The lead melts out into the dirt. Won $15US at Second Chance one year guessing the weight of a half pop(soda to some of ya'll) can of the lead that came out of pins. A couple of guys part filled a can from their fire, and ran this informal "lottery", $5 to get in and you guessed the weight of the lead "ingot". I split it with some other guy. Dam, I miss that shoot. Going to the few Second Chance Shoots I got to were the best vacations I've ever had.
"...I do NOT recommend 230 gr FMJ .45 ACP..." Ditto. Cast 230 FP's work better. FMJ's tend to bounce around a lot.
"...I had fun..." That's what it's about. "...my 8" bbl..." Try a 4". Your recovery time will likely get faster. Your one shot reload isn't a bad technique. Worked. Mind you, a full reload with your speed loaders(practice loading using drill purpose ammo. No powder or primer, but loaded the same otherwise) might give you more insurance though.
"...minumum power factor to meet for pin shoots..." That's daft, but rules is rules. No matter what else happened, you had fun.
Jerry Miculek is a class act. Long ago, before Jerry was the fastest gun alive, a buddy, Rawhide(big Eastwood fan), of mine beat him in a man-on-man shoot off at Second Chance. Miculek had his hand out in congratulations before my buddy realized he had won. Rawhide won $500US.
"...a timed game..." Yep, but the operative word is 'game'. What you use or whether or not you place, doesn't matter.