As butalbee said, take it slow. Even though you want to move onto a more involved relationship, you have to leave it up to him to make the first move... even though he has made gestures such as touching your leg, you really have let him.
With my boyfriend I didn't know he was a witness until we had been dating and very intimate for almost a year and a half. And when we were first dating I couldn't wait to "jump" him, and I don't regret it one bit that I made the first move. I had waited 6 months to meet him and we talked every day, if I didn't see him online I missed him. As to the PDA's, he has no problem with that... he is a very affectionate man. When I found out that he was a witness, that was the first thing that popped into my head... "oh my god, what if someone saw us and what would they do to him!" Last summer we were at the mall and someone that I knew from school passed us... I haven't spoken to her in a long time and she was not someone that I wanted to be around anymore so I didn't think twice about it... Well it ends up her family are witnesses and she is a real rebel (she has 3 kids outside of wedlock)so I don't think she follows the rules too much! Well anyway, she passed us, I looked at her and did't say anything, my boyfriend turned around at the same time and the look on her face was quite puzzling. He didn't even recognize her, and I didn't know that they knew eachother. Now I know why she gave us that look. But of course she was in no position to say anything. And we weren't doing anything, we were just standing in the parking lot talking, but he was holding my daughters hand at the time. That would have been great if we were and if she had let someone know... He told me (and I wasn't happy with that) if someone finds out oh well, then that is when we will deal with it. So he is waiting for someone to find out about us, by accident. I have even went with him to get a haircut, and you know how barbers and hairstylists talk when they know you... his father goes to the same place... hmmmmm.
But seriously, stay platonic unless he wants more, and he must tell you and have it out in the open. Please, you really don't want to be in the dark like I am... If you want more info on my situation I started a post about Interfaith Relationship, butalbee has one too and if you open up your browser to all posts there are a few others that I encourage you to read.
Good Luck