Some say grad students ok, not undergrad, others say no students period.  

Total time spent throughout the year may be significant, depending on the number of properties and amount of activities, but year end is no more difficult than any other time period they're doing. 

Never in the history of the Federal Reserve have prices gone down for any notable period of time.

I picked the short term ones (hold period < 1.5 yrs).

Further, Reg D 506 C offerings can accept new investors money right away, while other private placement exemptions require a 90 day waiting period for investments from investors with whom the sponsor did not have a prior relationship. 4.

They do not send periodic updates and you have to keep asking them for an update every month.

So I'm not sure how long of a loan tenor you're looking to offer with your owner financing sale, but my advice would be to use a higher interest rate while trying to keep the monthly (or whatever other period you use for payments) low. 

Quote from @V.G Jason: This is just that period of time in the investing cycle.

Period. 

I'd consider renting for a period of time and identify a particular area you'd like to eventually buy.