Earlier quoted context omitted.
Analytic philosophy has made my mind a razor. [...] Formal mathematical training (graduate) will do that to you too. I often find myself thinking with abstract algebra ideas (groups, vectors, vector spaces, commutation relations, etc).
I'm well trained in mathematics. It's certainly healthy. However, I often find that outside of their professional work, mathematicians are more willing to part with rigueur than the philosophers across the hall. Notice how most mathematicians aren't particularly interested in foundations of mathematics, for example.
I do recall a logic professor of mine jokingly say that mathematicians were afraid of logicians, and (more seriously) that the former thought the latter were unnecessarily precise. (I hope I'm remembering this right and not misrepresenting what he said)
I'm not sure about the superiority in rigour in the rest of philosophy (even if we narrow the meaning of that term to just analytic philosophy, some of whom sure are fond of their logic, symbols and attempting to sound "scientific" or rigorous). If anything, I'd say those analytic philosophers have math (or hard science) envy.
You're right about mathematicians not being very interested in the foundations of math. That's a consequence of the failure of the great foundational project in the early 20th century. From what I understand, most mathematicians have decided that such a foundation is not possible, and view themselves as moving on to doing the very practical business of math anyway. After all, the lack of a foundation has not prevented them from achieving many interesting (and often useful) results.
That said, there has continued to be interest in foundations for math from some logicians, and (at least according to my logic professor) it still might be possible to found math on logic yet. That's quite a bit out of my league, however, so I'm afraid I can't elaborate much. But if you're interested in that, I do recommend taking some courses in symbolic logic and in the philosophy of math.