I think Steve visited Steph because he saw she had visited Ted at work and they were having a hush-hush conversation. Steve doesn't know that Ted bunged her the £50k but I think his questioning of Steph about the TV and the sports package was more about him thinking that Steph has got a new bloke and he thinks it might be Ted.
I can't remember exactly, but didn't Steve say his painkillers were in the side pocket in his car, so why did Steph open the glove box? No doubt his addiction to painkillers is going to be used against him at some point. At the moment it seems that Steph and Steve have a good relationship in as much as she is grateful for what Steve did for Corbett at the time. I wonder if something will cause their relationship to sour and Steph will use this info against him.