So my question is, where can I find analysis tools or spreadsheets that I can use to work out the numbers and put together a formal/semi-official/convincing package to present to the prospective investors?  

If it is, I plan to invest a lot more.How did this work out for you?

Going into partnership solely because you’re friends usually doesn’t work out well.  

Work out a deal that way.

Paying me for wood and gutter work out of that money is actually paying me with my own money that I already had.

The only disadvantage would be that you would most likely not be able to get financing for this property, but if you have the cash to invest, it should work out very well for you. 

I am not expecting things to work out as you implied but prepare a good exit plan.

I attended an intro session today and my buddy signed up.

Most real estate seminars tend to be pep rally sessions to motivate individuals using various psychological techniques more than providing information and insights based on research that you can't find elsewhere.What seminars have you attended where it did not feel like blowing smoke up your glass?

Get a written agreement from the neighbor that they'll allow it to stay but it must be moved onto your property if it is every replaced.Talk to the neighbor and see what you can work out.