The exception is if I am renting to Students, and a Co-signing Parent wants to review from another state.

Crazy thing is this new market I'm looking at I've literally found ONE self manager that's not using a co-host.

You’re probably going to need a co-signer.  

We buy the $5 smoke detectors at Home Depot (9 v battery)We only use one CO detector per property (none have basements) and don't install a CO detector on an all electric house as there's no CO source.

Our current property is under contract and I am buying it under my name with a conventional loan and we intend to short term rent it and my wife is going to manage it (she currently manages STRs for a Co-hosting business).One of the lenders we talked to who is also an investor recommended that we start an LLC and rent the property to the LLC so that we can erase the DTI since we wouldn't be able to do that if we short term rent it.

Hi,I'm a co-owner of a full service real estate brokerage in Tucson, AZ, and we have a property management division that is in the growth phase.

I was also researching about getting a co-signer, but I was really hoping to just get a loan without a co-signer. 

Part of the issue is that I'm looking to buy a new investment property in the market in which the two others I own are located (Washington, DC), but the minimum price for property acquisition in that market without having to do a substantial amount of work is in the $300K range.Some background:I currently have two conventional, 30-year, fixed rate mortgages (one on my own, one with a co-borrower [my father]) on two single family homes and when I looked into getting pre-approved for another loan around this time last year, the lender I was going to use told me that my debt to income ratio was too high.

To establish responsibilities and outline the relationship, I have been advised to create a co-ownership agreement.

The most obvious is to increase my own salary (which is unlikely short term, since I'm already a high earner for my level of experience) or apply for a mortgage with a co-investor.What else have people done?