How are you applying it to STRs?

That way you are applying the same process to everyone, which avoids problems later.  

@Joe Splitrock, If @Jason Barton converts his replacement property to primary residence at some point the following criteria will apply.1.

The same applies to a Conventional purchase classified as investment.

I rent out 4 of the 5 bedrooms here and live in the 5th.Lets say I want to go get an apartment/studio in order to increase my productivity and eliminate distractions, and rent out my 5th bedroom.Let's say I want to sell the house at any time within the following 24 months.The 2 out of 5 year rule still applies right? 

Before getting into full design and costing, does anyone have any rule of thumb cost guidance to apply?

Either the tenants or the owner need to apply.

I recently read the book “Investing in Real Estate with no and low money down” by Brandon Turner and one question I had about syndications is I know the limited partners generally pay for the down payment and different fees but in terms of the loan itself from the bank do the general partners apply for that as a business loan?

If you go for quantity, you may not have enough profits (if any) after the deal is done.So again, what ever your taste is great, but giving advise to 2M people when the advise only applies to you is not fair for people reading this.Either way... 

Bonus depreciation can be applied to assets with a useful life of less than 20 years.