The quality of the original build and subsequent additions and remodels dictates a ton more of the condition whether the property is 150 years old or 5 years old....

If Landlord determines that the Tenant is in default of this Agreement, Landlord shall provide Tenant with a notice of default, and Tenant shall have a limited number of days to cure the default unless otherwise excepted: (a) for the failure to pay rent when due, Tenant shall have three (3) days to cure; ... or if the default constitutes a subsequent or continuing default within twelve (12) months of a written warning by Landlord of a similar violation, Landlord may deliver a written notice to Tenant specifying the default and Landlord's intent to terminate this Agreement.

Part of the reason is that the SFD needed some fixing up (which has subsequently been done).

Lenders and insurers are good mixing a commercial enterprise with a business entity.  

If I had to guess, this agent offered you a basic coverage form which is the most strippeddown coverage you can buy and subsequently the cheapest coverage.

On top of that, there is of course the issue of you having the cash on hand for the subsequent down payments and PITI reserves.Further, a lot of these folks that are in and out of deals uber fast are using a combination of cash and hard money financing. 

(Not to mention the subsequent time needed to negotiate the deal, build your team, put together the complicated financing, organize the complicated rehab, etc, etc, etc)...

Work with an attorney to prepare the documents, but then you can re-use them for subsequent deals.  

I am going to make the assumption that your intention is to run a legal enterprise and not trying to evade taxes or screw vendors, customers, etc.For most of your questions, the answer is going to be "it depends on what exactly you are going to do."  

I suspect he has discovered how to use other investors' money to improve their properties and make a profit for his enterprises and reinvests the profits into his own projects.