The only times this makes sense is if you are in a really hot market, especially seasonal ones where you might have 100% occupancy for the summer months or something.

Should I be budgeting significantly more sense people are in and out of the property versus them living in a long time? 

Wish you the best.If I was you, first step is evaluating costs associated with doing MTR and comparing with potential rental income to see if it makes sense to do LTR or MTR.

That makes sense.

Finally I came to my senses and served them a 'Notice to pay rent or vacate by the 10th of January' after which I plan to file an eviction.

With that in mind, I’m considering purchasing four rental units over the next four years to build a stream of income that could help supplement my retirement by age 68.The challenge I’m facing is that the deals I’ve come across so far don’t make financial sense.

You can BRRRR the deals that make sense and sell the rest.

So your 35% operating expenses makes sense and seem plenty conservative to me.  

I'd say to just go for the first one that makes sense and don't hold out looking for the unicorn of a deal.

Does that make sense?