I think you are overthinking this a bit, Greek.
If you'r holding her hand, permission to put your arm around her shoulders or her waist is implied ... just don't go for an ass grab! hahaha.
Don't even worry about the other 10% ... you will know if things are going well. If she is interested but she has a rule about never kissing on the first date, she will let you know because she doesn't want to give you a mixed signal. Take her at her word.
Carl.