Typically when one tenant in a joint tenancy situation moves out, the deposit stays with the property and continues to be held by the landlord in trust in case there are any damages or money owed when the property is ultimately returned. 

Known as “Project Wild Cat” it appears Amazon will be building a 20 acre (Yes 20 acre) fulfillment center that will bring 2,000 jobs to the Old Pueblo.[2] Geico to Build New Corporate Office in Tucson- Geico’s regional office is staying in Tucson and they will be adding 700 new jobs.

Are these the only drawings you provided to the contractor @Tim Wang?

Our average Section 8 tenant stays 10+ years unless I made a mistake when screening them.

After meeting with the contractors for the 3rd time they are requesting a blueprint, lesson number 48, get an engineer to draw your blueprints.

I would suggest the best way to go about this is to have the feasibility/zoning study done first (which sounds like this is what you're thinking too), then get pricing for full permit drawings and the construction from a design/build firm.

I owned a 6 unit small retail property many years ago and one thing that hurt our cash flow is when a tenant left the space sometimes stayed open for a few months at a time unlike a multi-family.Option 2 is to purchase and sell as biz condos

Make sure that your DTI stays below 40%-50% or you may have a hard time getting approve. 

.- Ripped up carpets and re-finished the hardwood- Fresh coat of paint- Laminate flooring in the bathroom- Stick on splash for the kitchen sink area- Few other minor repairs- Brand new stainless steel oven (all other appliances stayed the same)After all of this was finished up for about $5,000-$6,000 I was able to rent the unit out for just above market average in my area.

Nobody in this business would stay in it for long if homebuying or renting were firmly based in logic and wholly unemotional.