When analyzing potential rental properties you need to factor in a vacancy rate of 10% and another 5% for repairs and maintenance. 

I have been looking for property managers as I am not in the immediate area, but have struggled to find those that are highly recommended that still keep turnover costs reasonable (some 65%+ of first months rent) and maintenance-related fees reasonable as I expect mostly 1 year, college tenants.  

Your friend has about $7k per year cost of maintaining her property - if we ignore utilities (unless they are included in the condo fee, which sounds too low to cover all utilities) and maintenance. $280k divided by $7k is 40 years.

I have some options with business lines of credit as well, but before doing this I wanted to check on why more traditional loans are being discouraged in this case (and if this is common).

This should be a very common policy down there and shouldn't raise your premiums much, if at all.If he is sharing the profits with you it could be a great way to boost revenue, you just need to be aware of your increased liability. 

While I am new and probably not the best person to offer proper real estate investing advice at this point, I can tell you that one of the common themes I hear from talking to many successful investors echoes what @Jay Helms said above.

PM will give you a great baseline of practical skills for real estate investing i.e. handling leases, landlord tenant law, utility structures, maintenance, improvements, maximizing property value, keeping books, marketing, conflict management, working with contractors and vendors and a whole host of other skills and knowledge.

He tells me this is a common "takedown" for this type of sale.  

This is a very common and popular way to get started investing and it's highly encouraged.It's known as "house hacking" around here on the forums.

One common rule of thumb is to take 80% of the purchase price for improvements and 20% for land.Another way to do it is to look at the county's values for both land and improvements and use those to determine the percentage.