Of course you cannot predict the future, but for planned activities that either significantly interrupt occupancy, reduce income or increase expenses there is potentially a need to show good cash flow projections.

On the w9, you can only charge taxes on materials, you can't charge taxes on services, if you are paying cash (CA common practice, not saying it is legal) and expect to pay cash, then you're simply a licensed contractor doing an unlicensed activity (under the table).

Make sure to listen to all the BP podcasts, read the articles on the main blog and be active in these forums to learn a ton very quickly about any topic in real estate you want to know more about.This is also a great place to meet people that can be assets to your business.

Read books on investing in real estate, listen to the podcasts, attend webinars and stay active on the forums while connecting with other investors in your area and pick a niche.

It seems to have its ups and downs since I have been active in 1985.  

Brian, I'm still active in land acquisition.

This is an opportunity for buyers that are actively looking.  

REI seems very attractive, both from a passive and active perspective.  

Have you checked out a very active real estate investors group in the area. https://www.cfri.net.

There are a lot of folks who are very active here from the Bay Area and provide very valuable advise/feedback when needed.