These are things you will want to consult with a professional about. 

Everyone has a different outlook.

This also implies better B, C neighborhoods are not cash flow and unsophisticated investors are betting on a unrealistic outlook that will never happen.

I immediately brought in professionals, and we did 6 months of treatments, some of that with tenants in place and some after they left.

You and your wife have wonderful professional skills to allow for you goals .

Invest in yourself early.All of my answers should be vetted by a professional...but I'm trying my best.It is not necessary to form an LLC to do a lot of REI business activities. 

I already have 4 SFH in Cleveland and would like to connect with more RE professionals including RE agents/brokers. 

I would call it a red flag if they resist giving you everything you request for your DD document list quite quickly, their speed and thoroughness in response to that shows their willingness to sell imho.When you schedule your inspection you want all your professionals there at the same time to go through a single time, contractor, inspector, and any specialists you think you might need like roofer, engineer, etc.Also don’t feel pressured to make your DD and inspection time as limited as is common in SFR, give yourself 2-3 months at least, again, from when they deliver the docs you request.Besides financial DD you want to do physical DD not just on the property via inspections but visiting the area during day and night, weekdays and weekends, to ensure you have a feel for everything that’s happening at different times all the way around the block.

I use TD Ameritrade Institutional which is carefully managed by a professional with a minimal fee structure.  

I think these older neighborhoods have a lot of charm and location convenience that young professionals and some "empty nesters" are looking for (Rosewood has the additional advantage of having a decent elementary school!).