I've been hearing mixed opinions on starting out now, versus holding on to the money until the housing market dips. 

Are you concerned about the PMC doing the rehab to improve the property?

If I am familiar with an industry of home improvement contractors for example, and speak with them, meet with them, and they like the proposition to invest some money in me purchasing a property to re-sell, that is in of itself not an issue under the regulation for non-accredited? 

My mortgage balance is about 206k and the home is now worth about 280-290k after improvements and appreciation.

Rent control for Saint Paul passed with a 3% cap on annual rent increases and no mechanism for adjustments based on improvements or resetting to market rates between tenants.

CoC returns should include Rent, minus Principal, Interest, Taxes & Insurance (PITI), minus property management, minus repairs and capital improvements, minus advertising costs and anything else you need to run the property.Most realtors are not investors. 

It is technically possible to split and sell units in any property, but as @Marian Smith mentioned, it may mean setting up a condo type arrangement with HOA if the property wasn't built as a twin home with two separate units that have a split in the middle.Why are you doing this versus just selling the entire property?

How might it work if a tenant is offering to help cover repairs/improvements?

Never took depreciation or upkeep/capital improvement expenses on schedule E but always claimed full rent income.

There's a difference between vandalism and negligence; the latter is not usually criminally actionable when it comes to non-animated property (i.e. a car or a house versus a little kid or a pet).