For snow tires you should first make sure the tires have the M/S branding for mud and snow which rates them as winter tires. Cost effective brands include Bridgestone Blizzak and BF Goodrich Winter Slaloms.
Bridgestone Blizzak Tires are amazing tires for any sort of severe weather driving.
If you are visiting in the winter it is probably a good idea, because sometimes the snow is quite deep, or it is icy. If you are visiting in the summer- please don't waste your money on snow tires! There won't be any snow.
Directional tires are ideal for hard surfaces in good weather conditions. The best tires for driving in snow are snow tires.
In some places where it snows alot you have to buy snow tires. So if you have snow tires then yes you can drive if the snow is 8". But if you don't want to buy snow tires, you can get a chain and wrap it around all of your tires.
Yes, studs can be removed from snow tires.
You can install 4 snow tires but it is really not necessary. Only install the snow tires on the drive wheels.
yes, AT "all terrain" tires are MS "mud and snow" tires.
If you drive in snow you have to, regardless of the vehicle make. -The snow tires are your link to the road.
Snow tires cost slightly more than all weather tires. The actual cost of the snow tires would depend on the brand, style and size.
From what I know, they probably do not because snow tires have special pins build into it for gripping the snow/ice. It depends on the type of tire you are actually going to buy but generally mud tires are more expensive than snow tires.
if the studs are not installed they are just like regular snow tires
Michelin mud and snow tires get great traction, but if you want the best traction go with studded tires.