That would depend on the country and the prevailing traffic regulations. I think that it is safe to say that the answer would be a "yes", although it may be illegal where you are...
well yes they can because my uncle has a tractor in dominican republic and he can operate everything and he go with his tractor in th highway with license
yes
Your licence must include category K in order to drive a lawn tractor on the road. You do not need a licence to operate a lawn tractor on private land with no public access.
no, because a tractor is not allowed on a highway even if you do have a license to drive
yep
On a highway, no but you can on back roads.
yes
Yes
Yes you can operate but its only temporary you must get the licence to continues driving.
State laws vary widely. Some will only allow it on secondary highways, and almost all only allow it if the highway needs to be crossed when the highway transects the same owner's property. Check with your local Higway Patrol before doing this.
yes
Yes.