Not that I care, but the real estate commission seems to think it's worth investigating.

Based on my calculations and preliminary research, I have found that the Bay Area offers good returns from developing land, although acquiring level land and obtaining permits can be challenging.I have a few questions:1) Is it recommended to purchase a complete house plan from online sources like ePlans or similar websites and then customize the architectural design before submitting it to the municipality?

You have property rights, even though he may have some city leverage being a developer (tax revenue) you need to investigate the zoning allowances awarded to the parcel. 

Can anyone send me the info for that so I can investigate this further?

Yes, this is an area I am investigating.

What else should I investigate, if anything, and who do I contact to do that?

Perhaps.Just to add to what @Tom Gimer: points out, "When the buyer defaults": let's add that the seller can and sometimes does sue the buyer, and sometimes the seller is contacted by an advocacy group or an attorney and the attorney general is notified and if hanky panky is involved it can mean an investigation of bank fraud, wire fraud, violation of the Consumer Protection Act, violation of Dodd- Frank and some state specific charges.

(other than having cash/equivalent, preliminary title report, and the appropriate deed ready to go 'on hand')The MOST difficult part of this will be getting the lender to provide you with the reinstatement figure to bring the loan current (I do this and take title sub-to because it's actually easier to get the lender to provide a reinstatement than a full payoff). 

I sat through a 2 hour interview with the IRS criminal investigator its taken almost 3 years but when I asked her point blank.. she was like Nope we don't work on it this long and this hard and let it go. 

When these lenders were investigated; addresses turned out to be phony, licenses when claimed false and virtualy 61 of them wanted up front fees in order to process the loan.