I’ve had to evict the original tenants, got rid of a roach infestation, and the electrical seems iffy.

Look at the comps in your market, having extra storage is a bonus so as long as it has working electrical I wouldn't spend much time or money on it other than making sure it's clean for showings.

he has also asked for each electrical panel to be labeled and also gas meters to be labeled.

Hot water heater, furnace, gas, electrical box, HVAC, oil tank, plumbing pipes.

I think there may be a market for a lower density campground that offers a higher level of privacy per site with amenities (electric/water hookups, RV dump site, bathhouses, etc...) but...

Basic plumbing, electrical, HVAC knowledge will go a long way.

Here are the numbers I know so far:Rents4 units all currently occupied on one year leases- #1: 1/1 $995 monthly- #2: 1/1 $995 monthly- #3: 1/1 $995 monthly- #4: 2/1 $1,100 monthly- Gross rents: $4,085 monthlyExpenses- $12,070 taxes annually- $350 monthly insurance (my estimate, they have liability only right now)- $175 monthly landscaping- $120 water (electrical on separate meters, tenant pays)- Total expenses: $1,651 monthlyNOI around $2,434 before vacancy, maintenance, and management (although i would likely self-manage these)Property needs about $50K in other repairs and udpates from what I can see.

Quote from @John Williams: I would only support this because it's California where electric cars are most likely to be mandated and used.

Storm ponds, storm drains, flood ways or flood zones, underground electric, fiberoptics, etc.On the concept plan above. 

It was quite extensive, all new electrical, hvac, plumbing as well as foundation, painting, floors and yardwork and demo of shed.