Thanks for reaching out with some great questions! At the moment, we do not have a feature implemented that will help to filter or query results. It has been a top requested feature, and is something that our development team has been hard at work on. Hopefully we can get it implemented soon!
And yes! We are a mostly crowd-sourced resource, and if there's anything that the database is missing, we would love your help in getting it added to the site! I recommend heading to our Mapping Page for some tips on getting started.
Let me know if there's anything else that I can do to help!