Industrial property with several thousand square feet of vacant space that could be used for development. 

Find funding, buy a deeply discounted property, resell it to a rehabber.Again, wholesaling is legal in all states because you own the property. keep in mind though in Oregon if your not owner occupying it.. and you intend to resell.. you ALSO need a developers licenseyou need a bond and insurance... so again cant make these blanket statements yes it legal to buy and resell but you do have to have those licenses to do that... 

There has been so much development  in the past that it has really messed up the drainage in the Houston area, it doesn’t take a lot of rain to get the loacal bayous and water ways to break over their bank.

I want to ensure it's maintained properly without tenants fighting over it.

Make sure your contract is properly recorded with the state or you may face a fine. 

You will need to give proper notice and follow the procedures for eviction in Arkansas.

I own a rental property (a single family house) on a street where they're building a large "HUD 221(d)(4)" multifamily housing development across the street from the house. 

Expect prices on them to exceed $1.3 million.There are more in DC proper, but not a lot in the entire region in general.

I suggest you develop a fairly detailed scope of responsibilities for that PM, including how often you expect him to be there and exactly what kind of interactions, inspections, reporting and other activities & responsibilities you expect of him. 

Best of luck and keep us posted if something develops!