Wow massive backlog for this thread, did a quick search for "tertiary" and found no mention of what I'm seeing, so here I go.
It would appear that weapons' tertiary fire functions are constantly being triggered. While testing the Medpack functionality I had coded for Kayzee, I found that I did not need to press 'Q' to administer medpacks to my allies. If I so much as brushed against a wounded ally, the function would automatically go off. I'm not sure if you've noticed this yet, as I don't think many classes have tertiary attack functions coded for them. Anyways, I delved into your code, looking for what calls the tertiary fire function, and think the problem may lie around line 161 of the Begin Step event for the Character object. Whenever the if-block it's in returns false (which is pretty damn often), the Tertiary event occurs.
If you want help figuring out how to stop this, I'm willing to give it a go, but for the time being I wanted to point out what I had encountered.
edit: Disregard all that, that was only from a cursory inspection of some of the code and the assumption that the User Defined 3 event of weapons was triggered by the Q key. Apparently the function runs much much deeper than that and involves specific commands and the inputBike script. I don't really want to delve too deep into what you've written and make changes to it, so I'm going to leave my code for Kayzee's medpacks where it is (in User Defined 3) and allow you to figure out where it needs to go and how things need to be done. What's the purpose of User Defined 3 anyways if not the tertiary fire function?