I have classmates who don't like to write software (which is a big part of the University of Washington Masters program, although generally the software is in R). The future may not be bright for them, although they have good math skills. So if you really are considering a quant job, even in risk management, I'd get some background in programming languages. The other thing is that these programs are highly mathematical. Linear algebra is used a lot, not only for computation, but also for proofs (which I had not done before).
I did my Masters degree while working full time. The University of Washington program is one of the few programs that supports this. At least for me this required a complete commitment to school. I literally had no free time. If my wife had not done a Masters degree she probably would never have understood. If you did an MBA while working this may sound familiar.
I think that in any field it is a challenge these days to keep working as you get older. As with any group that is discriminated against (women, for example) you have to be better than the younger people.
All of this is ironic because for most people retirement options are limited so we all have to work longer. Yet people will not give us jobs because we have grey hair.
The issue of age has not arisen for me in finance, simply because the job options are so limited. I get lots of interviews in software, just many fewer job offers than I used to. But in finance the problem I've seen is that, despite the degree, I don't have finance experience. And the employers can hire experienced people these days with my level of software background who have worked in finance.
Bank profits have been way up for several years, so you'd think that this might improve the job market. But I have not been seeing this. Perhaps in a few years.