That being said, both sides of my corner lot do not have sidewalks, which I heard is a good thing but not sure.

The first photo of the front of the house shows mulch or dirt all over the entry sidewalk and those two bushes are overhanging the entry.

There are too many variables to answer your question, but it will basically depend on the zoning/density, the type of multifamily you want to build, the requirements for access/sidewalks, the requirements for storm water management, etc.I would recommend finding a local civil engineering firm that you can hire to do an analysis and preliminary design -- this will give you an idea of the number/type of units you can build.Only then can you get actual bids for development (when you know what you want to build). 

Instead, put an emphasis on safe sidewalks and bike lanes that offer an alternative to driving.

That's a *very* rough area and the home of "methadone mile", (the vicinity of the intersection of Mass Ave and Melnia Cass Blvd) where there are streets lined with pan handlers, drug dealers and addicts shooting up and passed out on the sidewalks and in doorways. 

Just city sidewalks. 

Check to see if you have to install any manholes, fire hydrants, curb, gutter, sidewalks, street signs, street lighting any specific street design or access requirements, Check DOT requirements for access, stop lights and permits, traffic studies, DWQ requirements for permits, permit fees and time frames.Once you have an idea of what you can build and what is required in terms of permitting and infrastructure you want to talk to some civil engineers and commercial general contractors that do the type of projects and build the type of buildings you want to build so you can get an idea of costs, time frame and requirements.

Regardless of the incident or circumstance, the landlord will be named in a lawsuit no matter what occurred at the property and at the sidewalk of the property too. 

I had him redo the lease to include all snow, and ice removal of the sidewalks or I wasn't signing the lease.

Check to see if you have to install any manholes, fire hydrants, curb, gutter, sidewalks, street signs, street lighting any specific street design or access requirements, Check DOT requirements for access, stop lights and permits, traffic studies, DWQ requirements for permits, permit fees and time frames.Once you have an idea of what you can build and what is required in terms of permitting and infrastructure you want to talk to some civil engineers, architects and commercial general contractors that do the type of projects and build the type of buildings you want to build so you can get an idea of costs, time frame and requirements.