Subpanel in shed (separate building)

Gentlemen: Re: whole house grounding. Do I have a problem? Was browsing thru earlier posts this thread, then when downstairs to check my grounding. Braid from around the two humongous conductors which go to the two sides of my circuit breaker panel is all bunched together and clamped to my neutral panel. I have a water meter which seems to have a solid metallic body, AND a 3/16ths solid jumper wire around it. Water pipe is apparently galvanized steel, from the main about 150 feet in front of the house. No ground rods anywhere. 200-amp service professionally installed about 21 years ago, replacing previous 50-ampservice. Range connected 220 volts via armored cable about 5/8 inch diameter. Armor on the cable has a short jumper to a water pipe. Water pipe was disconnected from the rest of the system during a remodel at about the same time. I don't see another connection to the plumbing anywhere else, altho ther is a very large clamp on the neutral plate with a fairly large wire going somewhere. Am I adequately (to code) grounded?

Today I purchased a used, but like new light-tower trailer with very few engine hours. It's a two wheeled unit with outriggers that has a diesel powered 7.5 kw generator that has a hand cranked tower with 4 halogen lights on top. It came with a copper rod and a cable on a retractable spool for grounding. I'll just be using it to light up my yard at night with an older very similar unit that I have had for some time. The older unit does not have the grounding cable; it didn't come with one, I never put one on, and I really never gave it a thought until today. Should I put one on? Thanks for any advice.