Cash on cash was 18%.Appreciation hasn't been great in the past but it's in a growing area and the "path of progress" since its a hike ride to the new light rail.Another kicker is that one of the current tenants is a sex offender. 

This is an open room kitchen, a U shape. 

The head plumber told me that the waste line has a "U Trap" which he didn't know about and that's where the back up happened. 

Did you buy cash or get a mortgage (in AU/US)?

I've told them that I would give them at least 48 hours notice, and they've told me that they'll sue if I don't pay them $50 each time I show the house, because they are worried that I will show the house to a registered sex offender.

You do a search and find that a registered sex offender occupies one of the units. 

He was told that the landlord would be coming over and bringing potential renters.Depending on where the property is, the tenant is looking at anything from a cop telling him to knock it off, up to prison time and registering on the sex offenders list for life. 

His solution was to rent to the very group that have the greatest difficulty finding access to housing: registered sex offenders.Ok.

Are you a U of R man?

Saying a pre-nup sets the precedent that you expect the marriage to fail is like saying giving condoms to kids encourages them to have sex.