I have a similar mead planned using cucumber, lime, lemonbalm, and basil.
I wouldn't use brown sugar, or corn syrup in it, but everything else sounds good. Also I second doing zest only for citrus additions.
ETA: Do freeze the cucumbers first, then thaw. Also, make sure this is something you will be able to keep your temperatures cool on. I attempted a cucumber wine once and did not pay attention to my temps nor did I get the fruit out after several days. It was one of the nastiest things I've ever fermented.