I have a couple of quick questions. I live in MD and i have a shed that is connected to my garage via a deck which is 100 feet long run. I have a sub panel in my garage and i want to run 2x20amp circuits in my shed. The circuits are for lighting and small power tools and exist today but run off a generator when i need them. I want to hardwire the circuits to the garage subpanel so my plan was to run 2x20amp residential circuits to the shed one for lights (15amp would do for lights) and one for the outlets.

I was told by an electrician that to do this I can run conduit under the deck and don't need to bury it as the two buildings are connected by the deck. So first question is that true? My understanding was that PVC conduit needs to be buried 18" and metal conduit 8".

I could also install a subpanel in the shed but i feel this would be complete overkill as I would always use the generator if i needed additional power above 20amps so as to not trip the garage subpanel. Second question does this sound OK and within code or is there a better way to do this? I have 200' UV 10/3 cable already to do the install and 60' of 1" PVC conduit that was given to me for this job by a friend. before I buy the extra conduit and bits to do this i wanted to run it by the experts here. Sorry if this is a newbie question I am an electrician trained in England and there are huge code differences in the US.