I have to agree that investing in a single rental unit is a bad move even in a good market. Even if you are lucky enough to get a good tenant, many things can happen and even good tenants can break a lease and disappear on you, then you have a vacant money pit. At least with multi-units you can spread the risk and usually have at least one unit rented to offset vacant units and provide cashflow. Even great tenants can have a sudden unexpected change in income like losing their job or having a health issue, or suddenly they start paying late which makes it tough to meet those mortgage payments on time. Or something big breaks like the refrigerator, and suddenly you're out a few hundred more than you calculated and your margin is wiped out.
If you end up doing this, here are a few more suggestions from a former landlord. Sign up for a credit screening service like
this one.
It will more than pay for itself. If a tenant refuses to give you their SS# so you can screen their credit - DO NOT RENT TO THEM!
Also, don't feel guilty about refusing to rent to smokers, or pet owners, or at the very least have pet owners pay an additional deposit along with signing a lease addendum. Pets can do a lot of damage and their owners could care less.
As for taxes, yes you can write off espenses, but don't forget about capital gains IF you are lucky enough to have a gain.
Finally, if you haven't done so already, get a few quotes for landlord insurance. This one may surprise you and you may need to adjust your calculations accordingly. It's not the same as homeowner's insurance so you can't use the same numbers.
It was this one expense that got me out of the business of single unit renting because it destroyed the margin so much.
Good luck in whatever you pursue.