Only if that is what is marked on the barrel. 22 LR and 22 WMR are not interchangeable.
Yes
As in .22 WMR? That is the full name of the cartridge- the .22 Winchester Magnum Rimfire- usually called the .22 magnum
There is a .22 WRF, and a .22 WMR. WRF is Winchester Rimfire. Bigger than a ,22 Long Rifle, but shorter than a .22 WMR- Winchester Magnum Rimfire. If someone is using the term .22 MRF, it is an inaccurate term.
No
.22 Mag shell only.
Yes
Winchester Magnum Rimfire (WMR)
No. The case of a 22 WMR is longer than that of a 22 lr, so the cartridge won't fit in a rifle that is chambered for 22 lr.
No.
In the case of firearms, it stands for Winchester Magnum Rimfire.
No