Hi Michael,
just some quick questions:
1. what kind of renovations will you have to do, and what are some upcoming reno's (1-5yrs)? - implied questions (condition/age of: roof, doors, windows, trims, boilers, electrical, plumbing, units - leaking/mold issues/ etc etc)
2. how old's the property? (will affect above)
3. why is the owner selling?
4. have you gotten in touch with the owner/broker? can you access actual #s or is this all proforma?
5. how's the rental rate in the area comparable to your units (what range)? and how are you determining this?
6. how familiar are you with the area? A, B, C, D class? are you familiar with the demographics and target renters?
7. what's the inventory like for rentals? (rent vs. own)... etc.
While I don't expect you to the questions above, I know that I'd personally want to have that information down pat as part of my DD. #s can always look good on paper, but the more practical questions/issues that you'll have to deal with can help determine if you have a dog or a deal.
Congrats on expanding your comfort zone!