Hey Fred! Thanks for coming out to the AMA!
I think whether you are able bodied or disabled, Development and programming is a PERFECT field! The only thing you need to be a good developer is the ability to problem solve.
Wordpress is a tool, just like any other tool. I have nothing wrong with it and it is a good way to freelance!
The only trick with freelancing is you need to be able to source your clients. Other than that, you can use whatever you want to solve whatever problem you are trying to solve!
Hope this helps!