I've also purchased a property through foreclosure that could have easily supported the debt on it but was managed so poorly that the owner couldn't keep it.I personally would feel comfortable with as much as 60% of my income going to debt service, however that would not be ideal - 50% or less keeps me happy and sleeping well at night.  

Its never evident in sales pitches as Roy mentioned but you can definitely ask them for that information and they should be comfortable sharing that information with you.

I've messed with all three of those during my engineering studies but not enough to be comfortable building anything.

It isn't done here often, so make sure you discuss it with a lawyer that you plan on using ahead of time so they are comfortable with it.

It is not an absolute requirement but Texas more than other states seems to focus on other than same-day transactions due to heavier oversight by their state regulatory body, which does make transactional funders less comfortable. 

Regardless of what I got I still felt more comfortable in construction.  

Regardless of that I let more comfortable in the construction business.  

It's all dependent on your comfortability with risk and what $# makes you feel comfortable with that risk.   ...or your desperation to rent the property...

My comfort zone for renting properties is atleast five, this way if you do have a bad tenant of need major work done on the property, your other properties help offset the financial burden.  

The ones I've seen have more work than I'd be comfortable with.