For now, I hardly do any night gaming. Being in university makes day game alot more convenient.

After some well thought out text game, I managed to convince this HB to hang out with me. She's known me for about a year, during which we had very little contact. We set up the date a week in advance. HB has a boyfriend.

The day arrives, HB reaches my place earlier than expected (she's picking me up). I tell her wait in her car. We reach the mall and I convince her to watch a movie with me, which is in 2 hours. During this time, I tease her, we're laughing, we're flirting. (she may naturally be flirty with everyone though..)

*She wanted to go to a female lingerie store. I was very reluctant and she didn't insist I go with her, but I went for like 2 minutes. Then I made a joke an left, waiting for her outside. I wasn't sure if by staying I was losing my frame.(?)

We reach the theatre, and its smelly and hot(its never this way). I'm looking bad. The manager tells us we can come watch another movie within the week for free(instant 2nd date). After a few minutes they fixed the problems and it was all good.

The movie is showing and its really funny(21jumpstreet). Everytime she's laughing or something outrageous happened, she would put her head on my shoulder or chest. She's also sitting and leaning towards me. But I was not sure when would be a good time, so I did not go for a kclose.

We leave, she drives me home. I ask her if she wants to come inside for some coffee, she's preoccupied with finding my house and doesn't reply. I don't repeat. She hugs me goodbye.

Did I miss any opportunities here?

man, personally i would say that if you knew she had a boyfriend, yet were still going to try it on with her, and then after her taking you to a damn lingerie store that you should DEFINITELY have gone for it when she was being really physical with you! (speaking of the lingerie store, id say that would be an awesome place to get into a flirtacious sexual vibe with her.) its sounds like shes definitely interested.. but too many more trips to the mall without escalating and you will go friend zone hard.
overall id say at least make your intentions clear. if shes not into it after that, then on to the next one buddy!