There was another thread a few years ago about weather underground changing their API key policy and not allowing access.
As far as the API expiring, I found that my old API key was gone, and created a new one on weather underground, and found that it had an expiration date six months from when I created it.
Yes I am referring to using the PWS as the weather data source. The advantage is that I would not have to worry about the api key expiring, or the web site being purchased by someone else and being screwed up.
As far as attempting to modify code, I once attempted to modify the mouse driver in linux to support a different mouse. I wasted a bunch of time trying to figure out even which files the part I wanted to change was buried in. I never found it. These projects usually have a steep learning curve that one must climb before one can do anything useful in them. I am a hardware guy, and have not done serious programming in 20 years. It is fine to point me at the source code, and for you it might be a trivial change, but for anyone else the learning curve to be able to do anything useful is a huge barrier to even making a trivial change.