I do not think there is an actual code but general rule of thumb is 1 foot between all utilities.
No you shouldn't. It will fail inspection. Use electrical (grey) conduit. It is about the same price and has the proper electrical insulating properties required. The thicker PVC(schedule 40) is best, although schedule 80 is acceptable. (Schedule 40 is required for underground service feeders.)
Yes, it is 36" clearance in front of the box and 30" clearance on either side of a service panel or disconnect.
There is no maximum required clearance
The required code for toilet clearance in a residential building is typically 15 inches of clearance on each side of the toilet and 21 inches of clearance in front of the toilet.
Per NEC 110.26, two exits are required unless: 1) the working clearance is double what is required, or 2) there is a "continuous and unobstructed way of exit or travel"
4/0 Aluminum or 2/0 Copper type USE.
Phase to phase clearance should be around 11.5 inches.
You are not required to have a general contractors lic in MD when working on commercial property. You do how ever need a lic to do any Plumbing, electrical, HVAC no matter the property type. For a home you are required to have a MHIC Lic to perform work unless it is your home. Then you can act as the General and sub out the work to contractors that have plumbing, Electrical, HVAC lic.If you do any home improvement work without a license in Maryland, and the customer refuses to pay you, you have no legal recourse.
No unfortunately a home inspection usually only covers structural and electrical, you would need a plumbing inspection as well which covers spa's, sewer line, taps, baths and everything else plumbing related. More information is here http://www.prepurchaseplumbinginspections.com.au
UF cable(underground Feeder) Looks like romex, gray jacket. usually approved for direct burial. Check local electrical codes for burial depths, or if conduit is required. if conduit is required use THHN or THHN-2
not for your own property.
yes