I see no downside to learning a new language on the side. Even if you never use it professionally, it's still fun to learn new things and it will certainly help you think in different ways. My suggestion is to use the languages that keep you close to hardware:
C++ with Arduinos. This lets you connect to other chips that will give you your ADCs, DACs, GPIO, etc.
Python with the Raspberry Pis and other single board computers
The LINX toolkit lets you get your feet wet with the above hardware in LabVIEW. You can go back and forth and see how each tool handles the same task.
Verilog so you can get back to graphical programming with the IP integrator. This will also get you high speed ADCs and DACs if you need that performance.
In other good news, you're now forced into a clear line between the UI and the backend. I suggest Javascript/HTML for the UI.