Being a small guy, watch when you go for that can opener. If you get yourself to one side too much, you'll get your back taken.
I myself am the smallest in my class and have had someone try that to me. I locked arm (pressed my head to the floor initially) and waited for them to pull. I then grabbed and pulled their arm across me which set me up with for an arm bar or to take their back. I chose the latter.
I always tell people that the only thing you can effectively do from the guard is pass it. Anything else sets you up to be submitted.