I've read so many articles/blogs, etc about all of this, but want to actually talk to someone who's having success with a system (and who has a mix of flipping and rentals).

Yes, those pro sports teams in Miami and Ohio and Alabama and elsewhere will definitely be hurt :) I know the economic impact will be severe, but part of me would be delighted to see the NCAA brought low.  

Often times these restrictions include only allowing a small percentage of rentals or in some cases restrictions on what can occupy a space when it’s a mixed use community.

A mix of rye , rebel and K 31 .

It's great that you want to help, but friends & biz often don't mix well.

Personally, I have a mixed portfolio of 30 year mortgages, ARMs, and commercial loans with variable rates at 5/10 year increments.

Mixed commercial and residential a bit more trickier but doable

I am trying to gage whether it is more beneficial to claim this property as an investment property or mixed use property or as a sole residential property for tax reasons. 

business is business. times I've mixed charity & business have not had good outcomes. 

You're also in commercial territory anytime there's a retail/office component mixed in with apartments (any number).