One thing I realized after booking with PP a couple of times is that the site is an aggregate of many other SP and agencies (K604,XDS,ETC) in hopes of increasing advertisement. So if the SP is affiliated with an agency and the agency is known to have similar/accurate photos of the SP then PP will also have accurate representations of the girls. However, I do not think that PP enforces SP or agencies to have accurate photos so like LL many girls have enhanced/favorable or inaccurate photos.
To answer your second question, in my experience PP is completely legit in that they are just the middle person trying to get more customers for the agencies and SP. But I would suggest contacting the SP directly or through the actual agency over contacting PP since their customer service is pretty bad and I was told to eat shit by the phone person for asking a couple of questions.
The last part of your question is difficult to answer because I feel like this is always a YMMV situation, but the times I have booked I have been able to get most if not all of the services listed on PP.
Hope this answers your questions!