In my area, I've seen 2 postings that say "Warning: this girl works with LE" .. "my friend got busted".

What are the signs that a lady is not likely LE (if she does not yet have a review)? Please don't flame .. I just thought some hobbyist are more risk-taking and will try a lady without prior reviews, because he wants to review her first.

I thought maybe she's unlikely to be LE if  ....

1) She has several ad postings on Bpage - like several ads in 2 - 3 months?

2) Really nude photos, not just pics with clothing?

3) Have a disclaimer saying 'not an offer for p"

What else in your experience?

There is no surefire way to know.  

LE can do what they want and twist what they want into what they want it to be.  

Disclaimers are worthless and the purest admission of guilt in existence.  

There are no entrapment laws either.  The old grab my dick, grab my boob trick is a joke as well as directly asking "are you a cop" is worthless.    

When an ad is placed, it can be set up to repost itself every couple of days, so forget that theory as well.  

There are NO guarantees, but sticking with well reviewed ladies with a good reputation who SCREEN is your best bet.  Beware of the "cheap and right now."  
 
And DO Not Forget, LE can use civilians as confidential informants as well.  Civilians can do whatever they want and then just inform back to LE.  They can drink alcohol, and they can go through with the whole main event, then just rat you out.  

I would strongly suggest that you NOT try to find an easy or cheaper way.

My experience stay away from Backpage and Craigslist ( unless you're buying tools)
Besides the quality of girls there is pretty bad. Since I've been using TER and P411 I've not experienced any drama or bad experiences.

There is no way to know for sure, if she is not well reviewed. LE can and does all of the things you mentioned above.
You would be much better off to stick with well reviewed ladies. If you don't you take the chance of being busted or robbed. And don't believe all tha ads you see that claim certain ladies work with LE, many of those are posted by other providers or clients who have been turned down.
Whatever you decide to do, stay safe and have fun!

1) Several ads over a long period of time might be a good sign but it is not proof she is not LE. And if she has actually been active for a long period of time, there is a good chance there is a review of her here or elsewhere.

2) This means absolutely nothing. There was a post recently of someone who was busted. He had a link to the ad and it was all nude photos. LE can get the pics wherever they want.

3) The disclaimer is also meaningless. It's like them saying "I'm not a cop" in their ads.

It's pretty risky to meet an unreviewed independent girl on backpage or CL, but I guess there are some ways to minimize it:

1) If she is visiting from out of town and has ads posted across the country in her home town and other places she's visited that don't overlap and have the same phone number it's less likely she is LE. (LE doesn't have to go through all that trouble to trick people, most people don't do that much research). Do a web search on her phone number.

2) If she offers outcall only it is less likely than she is LE. It's easiest for LE to set up an incall sting at a hotel or an apartment and arrest everyone who shows up. Going around to peoples locations arresting them is a lot more work.

3) If she has reviews elsewhere from people who have actually seen her it is less likely she is LE.

None of these things are 100% proof that you will be safe but they will provide a lesser risk relative to just responding to an ad out of the blue.