Based on your post, it seems like you have an appetite to learn and have some control in the outcome. 

The higher you are leveraged, the more of a bite a rate increase is going to take from your ability to stay positively geared.The older-guy view aside ... if your young and have an appetite for debt and are comfortable with the risks, working without a net will allow you to grow faster ... just be certain you have all the exits covered.

Kitchen fire + no commercial kitchen built in fire suppression system + no insurance = ?

Most developers will not consider a speculative deal without proforma of 20% yield.So to specifically answer your question, you need to determine the level of appetite of your investors to assess what rate of return they are seeking with respect to their perceived level of risk. 

Specifically fire code; fire escapes, fire suppression systems, stairwells, doors, etc.2) Insurance costs.3) Elevators.4) Parking.5) Security.These are over and above what I would already be looking at with a single story garden style complex.

@Evan McLeishIt changes from time to time depending on a lender's portfolio mix and their appetite for a certain kind of financing.  

It is up to your appetite.

. $$$, cash flow and appetite for living in not the best areas will determine your location.

Continued new construction in the area will suppress the value of your purchase, but not depreciate it.

Some lenders have more appetite towards certain properties and Risks then others.