GR setup the license so they don't have to verify product or licenses.
I don't think they will "get back to you" except maybe to say they don't review products.
Setting up section 15 in the OGL is simple. Include everything from section 15 from the works you're deriving from (no need for repeats!!), then include your work last with the same info.
I like to copy everything out into a Word document, eliminate duplicates, and then order alphabetically keeping the SRD stuff at the top of the list. I've seen many publishers use 8pt font but with the list of resources used, I would budget two pages for the OGL.
Also, if you have ANY IP (intellectual property) be sure to call it out at the beginning of the book. This includes proper names, setting material, etc. You only have to designate the rules stuff as OGL.