Best left to a gunsmith
You will have to provide the end use for the pistol for anyone to even begin to try to answer this question. Also, your budget.
Yes. Not the best choice, but yes.
This is a problem best left to a qualified gunsmith.
Impossible to answer without knowing intended use, even then, it will be an opinion.
For what? Accuracy, target shooting or beasts of the forest?
Best to ask a gunsmith for help.
H&K USP45, hands down. Imo its the best designed pistol in the market 2day. Great looking, reliable and accurate. My cousin has one as service pistol and it has never jammed.
Your best bet is to find a gunsmith and ask for help.
Best left to a gunsmith. They were not the most "sturdy" pistols to begin with.
Best left to a gunsmith.
You will have to follow your states hunting regulations for mimimum caliber. Best is a relative term that only you can answer based on your skills.