Answering in order:
1. Loads like the 230 grain +P HST wring the last ounce of possible power out of the .45 ACP. I've seen one-inch diameter perfectly expanded HST bullets from this load dug out of flesh. However, it's being achieved at the expense of additional recoil and more battering of the gun, to which 1911s are particularly sensitive. If you need flat trajectory for long shots, the 185 grain +P JHP .45 ACP comes into its own. Again, though, you're putting more wear on the gun and on your hand. Your call.
HST +P .45 ACP 230 grain has worked great in the field. Oddly enough, I can't find any shootings with the standard pressure version, but it's certainly a promising load.
2. I use Winchester 127 grain +P+ or Speer 124 grain +P, personally, to load the baby Kahr 9mm.