Does anyone know if you can use a cost segregation studies for STR properties that you may have outside the US (and use it against your US W2 income)?

My advice, don't go for a homerun, a base hit is just fine.. buy something solid and get educated about your market.Its sounds like you are spreading yourself a little thin with all those markets to study. 

Civil Suit they would need to prove damages I believe.

As long as you are able to prove its not a "true log cabin" you should be fine.Materials listed, it looks like that may be one that just resembles, but be sure to ask your agent first, or the seller before you spend time and $ on it. 

If so, is that assuming that the builder builds at cost (and "proves" it by providing invoices/etc. by the subs)?

I learned that I really enjoy originating notes and thought my services could prove profitable to other investors.I would like to start a full-service business where I help landlords convert their rental properties into low-effort and profitable notes.

Some locations may have "pockets" of high density student housing that proves to be more popular than a house across from one section of campus.

Can they prove how long it takes to rent a vacant property?

The conversation was that you wanted us to jump through hoops and prove who we were and my people aren’t trained for this.

There are specific rules for 1031 exchanges including:The replacement property must be identified within 45 days of transferring the relinquished property.The replacement property must be received within 180 days after the transfer of the relinquished property or the due date of the taxpayer's tax return, whichever is earlier.Special rules apply for exchanges between related parties (defined in § 267(b) or 707(b)(1)).Real property located in the United States and real property located outside the United States are not considered property of like kind.Cost Segregation StudiesA Cost Segregation study is an IRS approved federal income tax tool that increases near term cash flow by utilizing shorter recovery periods for depreciation to accelerate return on investment.