What is the difference between the V3 hex and the V3 tungsten

The difference is the type of spikes on the bottom of the ice grips. The V3 Tungsten has tungsten carbide spikes while the V3 HEX has Carbon Steel Hex spikes.

I will be in & out of the snow & ice a lot are they safe for walking indoors on hard services like concrete? What about carpet? Safe to drive with?

Not the best for bare concrete. They may wear out quicker and don't provide the best support because the studs are grouped towards the middle of your heel. Big no no for wood floors unless you don't mind making little holes in the floor. Ok for carpet if you don't drag your feet. They may grab or stick if you drag. I'm not entirely sure here and basing my opinion on some door mats. They don't feel right to me when driving. The studs scrape and stick a little in the grooves on my pedals

Im looking fo something mainly used for winter hiking. Are theses ice cleats durable enough or is a different style a better fit for hiking?

These cleats are very durable and fit extremely well over a boot. I would say these are best for city use on icy sidewalks and streets, because the cleats are quite short—only 1/8" long. These may not be long enough to make any difference in deeper snow on a trail. Hope this helps.

Do these come with extra spikes?

No, these ice cleats do not come with extra spikes. These grippers have non-removable spikes, so there is no way to replace them. That being said, the ice cleats are durable enough that you should not have to worry about replacing the spikes or entire unit until after having used them a lot.