Having worked at a Deli that also served sandwiches, we HAD to change our gloves in between sandwiches. Im not sure if its a health thing or just where I worked, but I would ask someone to change gloves.
Knives should be sprayed and sanitized after every use. This I know is a health code, so asking them to do that shouldnt be a problem.
I always say Im allergic when I think/know Im gonna get the, yeah, sure, no cheese look. That way they take it more seriously and I get less attitude back.
I miss Blimpies, they were so good.