Depending on configuration of your kitchen, you might look at 2-3 slabs (8').

This seems very odd to me, as the current configuration involves just a metal stand that allows the camera about 30deg of up-down movement.

. $69000 Median home cost in the area (zip code) is $124,900*The property right beside it with same configuration/size was tax assessed in 2011 at $20k)Property was built in 1940 and its got a new new 5 yr. old roof and sidings.

Some configurations have an extra meter to control these common areas paid for by the landlord.  

Any advice on configurations (# bedrooms/baths) to maximize returns?

Basically make the hallway be part of the inside of the apartment instead of the current awkward configuration. 

It can be configured a number of different ways. 

The Spreadsheet is also configured to turn a cell red alerting us to an undesired answer to a question, i.e. how many people in the household smoke?

-What do you think is the best way to configure the rental spaces? 

I'm a CPA, I generally would not recommend a CPA for a simple tax configuration as this.