I don't see it on the Oregon Real Estate site: https://www.oregon.gov/rea/licensing/Pages/licensing.aspx 

Looked around the site, I only see lenders, property managers, agents, brokers, etc. but not developers?

The Detailed Engineering Cost Estimate Approach is typically used for the purchase of used property.SURVEY OR LETTER APPROACHOnce a site inspection has been completed and all components of a property have been determined, your specialist will send a survey or letter to the contractors or subcontractors to request they provide the cost of each of the items.

To help support that avatar, try and have on-site parking and ideally a place where a large work truck can be parked without issue (think fully decked out F-350). 

What tenant screening sites has everyone had luck with?

Buying site unseen is a huge risk unless the buyer and wholesaler have a history doing deals together.My buyers trust the deals that I bring them, but I also provide them with in-depth inspection reports along with photos/videos of the inspection along with multiple cost to completes through multiple contractors.

I purchase the materials and have them delivered or deliver them to the job site.

With Google, Yelp, Facebook reviews as well as what is on their site and what type of content they are posting on their social media pages....

I was building a new laundromat in the best retail area of our town when our job site got its tools and copper robbed for the second time.

That's not exactly an up and coming area -- I'd research who built them - can likely find that by going to the SG County Recorded Docs site or by seeing who pulled the permits during const -- Wichita has been on a duplex building boom -- look at the tax value -- They probably have that or less in it on the build - I also doubt they were built to be quality long term -- things such as the trim/cabinets etc -- they all look like the cheapest stuff a guy could buy - if the cabinets aren't oak and there is MDF or pine trim and pre-hung doors with engineered wood jams I'd run.  2-3 yrs ago for $180k -205 or so you could buy duplexes in Maize, Kechi, Valley center all day to builders that were selling them off to investors - not worth that in that area.