No. They are totally different size and shape cartridges. 22LR si rimfire, 22 Hornet is a centerfire.
Probabably 22LR. Have it checked by a gunsmith.
No. The .22 LR is a straight sided RIMFIRE cartridge. The Hornet is a bottlenecked CENTERFIRE cartridge. The chamber of a Hornet is MUCH bigger- you could not get a Hornet into a .22 LR chamber- and the firing pin would hit in the wrong place.
Yes
IF the revolver is marked ".22 LR" yes. If it is marked ".22 WMR" or .22 Mag" or " .22 WRF", then NO.
No. It is a 22LR semiauto, and needs 22 LR ammo to cycle the action.
The rifle will shoot .22lr .22 short, and .22 long. Only .22lr will cycle the action and load the next round. .22 Short and long will function as bolt action only.
A qualified gunsmith will ream (machine ) your chamber to the K dimensions, and then you simply shoot your regular hornet ammo in the gun. The pressure from firing will expand the brass of your cartridge to the exact dimensions of your new chamber. When you extract the case, it is a k-hornet case. Simply reload accordingly. This is known as fire forming.
four
Not safely. The 22 lr is a slightly smaller case dimension, so it'll split in the cambe of a 22 mag gun, and vent gas out the back.
22LR
Anything is possible if you have enough money, time and a good gunsmith.