TER General Board
First let me congratulate you on becoming a VIP member of TER. You are right that this board is a great resource for hobbyists. It's a great resource for providers too. 
Your research is paying off. You have good ideas about staying safe. 1)Finding ladies who have several recent reviews from hobbyists with many reviews or who are whitelisted. 2)Seek providers with real websites. 3)Check on LE activity in your area.
Here are a couple more ideas for you:
1) Network with hobbyists in your area to share information.
For legal reasons LE activity shouldn't be posted on a board until it has been made public, but your hobby friends might send you an e-mail if they hear about something.
Your hobbyist friends may also share info about ladies who are 'under the radar' (usually part-time ladies who don't advertise publicly)
Sometimes important information doesn't make it to the boards (a lady seemed high in session, or has a pimp, or does BBFS, or has an STD ...) because the gent writing the review wants to be nice or doesn't have proof. Your hobbyist friends are likely to share this kind of info with you.
2) Contact the providers you are interested in.
Ask them where their reviews are posted. There are many boards. Some ladies might only have a couple reviews on TER, but many more reviews on other boards. These other reviews might give you a better sense of how safe she is.
Evaluate her professionalism by how your communication goes. If she seems scattered, perhaps she is.
Does she screen you thoroughly? If she doesn't screen you, she is showing you that she is lax about her own safety. Do you think she is careful about your safety?
You asked if there is a way to find out about LE activity in an area. We are blessed here in Seattle with a plethora of local escort review boards. Once LE busts make it public, this info is posted on the boards. This may be true in your area too.
Best Wishes and Happy Hobbying,
Sarah Nicole of Seattle