Can I use this saw on a standard US outlet?

No. It is rated 220 V, so it needs a 220–240 V supply or a step-up transformer. Running it on 120 V will not work and can damage the motor.

What thickness of wood can an 8-inch blade cut?

An 8-inch blade gives roughly 2.5 inches of cut depth at 90 degrees, less at bevel. Real depth depends on the blade and the saw's arbor height, so check the manual.

Is 800 W enough for hardwood?

It is fine for thin boards and softwood. Thick hardwood or long rips will slow the blade and may stall it, so take light passes.

Does it come with a fence and miter gauge?

The listing does not confirm accessories. Compact saws in this class usually include a basic rip fence and miter gauge, but confirm with the seller before buying.

How does it compare with a full-size contractor saw?

It is smaller, lighter and easier to store, but has a smaller table, less rip capacity and a weaker motor. Choose it for space and light work, not for framing or cabinet making.