Here's info on screening tenants here from BP - and a link to a screening partner.BP's Tenant Screening - Ultimate GuideGood luck.

Hi, I’m highly considering a mixed use building which includes a few residential units and a couple commercial units.

I would find a property that can provide you both.I used to aim for 8% cash on cash return + 4% appreciationGiven where the market is now, it is likely hard to find 8% cash-on cash and a 4% appreciation.I think 4% cash-on cash and 4% appreciation is do-able.

I sat in on a lot of the meetings with owners/city and it seems for the most part to me, the city is just not interesting in AirBnB and as an investor, that's not a good place to be or be right.There will always be probably a few people who skirt the law or think they have a good workaround, but often catch 22. 

As both a realtor and a general contractor.

My original SFR was 1100sf and I added 2 units: an 800sf SB9 unit and a 750sf ADU (converted garage plus addition).

Bathrooms if you can zero threshold people love those and as they age out they need it anyway but that would be for main level. 

I helped the owner structure the seller finance and off-market offer to be closed more easily (more accessible to the buyer) through mixed financing and a lower price.

Do you have your finances in order now and a pre-approval so you know what price point you should be targeting?

I believe your witness to the smell and a signed affidavit from a neighbor or two would be enough to evict.