Some people love 9 millimeter, some people love .40 S&W, some people love .45 ACP, etc. It's strictly a matter of opinion, and very difficult to answer because different calibers are designed/intended for different things, and there isn't really any single "all-purpose" caliber. A .22 target pistol is a great small varmint gun, but a very poor choice for concealed carry. A .45 ACP is a great choice for concealed carry but a very poor choice for hunting squirrels. A .500 S&W is a great hunting gun for larger game, but a very poor choice for concealed carry, or squirrel hunting, etc.
It all depends on you, your pocketbook, your skills.
Best to ask a gunsmith for help
Can't be answered without knowing what caliber, intended use, make of firearm
Yes, colt makes a few different versions of the 22 caliber handgun such as the Woodsman, and Challenger.
Assuming you mean a bullet fired from a .22 caliber handgun, the answer is, yes, it can, but it depends on several variables.
Its the size of the bullet that the gun is made for. its the caliber that a handgun uses
It should be marked as to caliber on the barrel.
No.
Probably. It would likely refer to a handgun that fires a .45 caliber ACP, or .45 GAP or an older .45 caliber revolver round.
.32 caliber. In a semi auto handgun, probably .32 ACP
45 has the larger projectile. Size of the handgun will vary.
$489!!