You haven't mentioned any software skills. I would recommend develop whatever skills you have in that area. The ability to program is becoming as important as literacy and numeracy. Even more so for a mathematician.
My bias is that I have a PhD in math and have been a software engineer for the last 10+ years. I have worked in a lot of different areas and that has largely been because of the combination of math and software (and luck).
I didn't mention programming because I don't see myself being a developer, which I knew would get a lot of attention. I like solving problems with programming, but I don't see myself writing a webapp to collect information for someone to steal.
Computer Science is my secret lover. I initially studied that, but my university focused on producing java devs for industry and didn't do the "science" of computer science. I still work through books when I have time though. About half-way with TAOCP V1.
My reason for asking the question is two-fold: some badly needed reassurance that I have not rolled myself into a hole (I think it was a design flaw that we cannot re-roll characters in real life) and getting a broader perspective on potential places to keep in mind - in terms of extra-curricular skills that I need to gather along the way.