What I often see being a mistake is people ordering a cost segregation study before speaking with their accountant to see if it would benefit them on their return.What a cost segregation study does is analyze a property further to identify assets that be classified with a shorter asset life than 27.5 or 39 years.The issue when getting an 'estimate' from a cost segregation study company is that they are not accountants(more specifically not your accountant).

Is there a particular site thats good for searching multi-family specific?

If you think they are dealing you need to make the late night visits uncomfortable by dealing with any specific lease violations regarding quiet hours.   

(This is a general statement not market specific) Condos have a lot more to deal with that TH/Apt, these two are pretty cut and dry compared to Condos. 

Most likely no tax difference, unless the annual interest amount approaches your standard deduction of $12k ish.All being relatively equal, I'd take the path of fastest removal of her from title.   

If I can help with any specific questions feel free to DM me anytime.

Also if there are any specific zip code or neighborhood in Memphis which are more preffered for short term rental than other zip codes?

Looking for a solid company where I can verify reviews and listings..I’ve had a few that started off well, I thought, but when I would ask specific questions the correspondence  stopped.  

The same goes for people creating groups specifically for a certain race, religion, etc.

You can still take depreciation, the deduction is deferred until you can use it in a later tax year.The most effective way to fix this is to get your spouse to qualify as a real estate investor per the IRS.