BTW, what is a good indicator that the real estate market is stable there?

So far the local banks are indicating a problem with the quick timeline.

As Andreas indicated, you can use the assignment and allonge documents used for the transfer from seller to your entity as a template.  

The leasing or rental of units in those two family homes in which the owner occupies one apartment of that home as his residence is not covered by this law unless: The homeseeker or renter is a recipient of public assistance or housing subsidy; or,The leasing or rental process utilized the services of a person or organization whose business includes engaging in residental real estate related transactions; or,The availability of such unit is made known by making, printing, publishing, or causing to be made printed or published any notice, statement, or advertisement with respect to the rental of such a unit that indicates any preference limitation, exclusion or discrimination based upon race, color, religion, sex, sexual orientation, national origin, ancestry, children, marital status, handicap, veteran status, or public assistance or housing subsidy recipiency.The following text is effective 07/01/93  

So I would have rejected the bathroom fan request unless the current one was broken and you indicated they would receive a bathroom with a working fan (which you would want, for mold purposes).

What would this indicate?

Court records, code violations (especially when the code violation indicates if the house is vacant or not), and crime reports can identify good leads.  

@Justin Tortorich Its worse than your brief summary indicates, and the city appears to be enforcing it.  

Special assessments for something like this is an indication of poor money management.

For instance, Closing fee will be around $1,200Lender's Title will be around $1,000 (or less)Recording fees will be around $140 - Cant say if you will have to pay transfer tax to the City because you have not indicated which suburb the property is in.