Leo says that Audacity is open source and works great, but it can be buggy. Cool Edit was the ideal open source option, but Adobe bought it and turned it into Audition. It is now the champagne of audio editing programs, but it's also hundreds of dollars. Unless he has a lot of problems with Audacity, Leo recommends just sticking with that.
Leo says if he's getting a green video signal, that usually is a sign of a bad video card or driver. Disabling Hardware Acceleration may help. Here's an article from Lifehacker on how.
It could also be Flash that's broken. Try reinstalling Flash, or switch to the HTML5 version of YouTube.
Leo says that Adobe makes a flash player for Android if he has Gingerbread OS or later. Go to play.google.com and search for "Adobe Flash Player". They have announced they'll be discontinuing it though, so he should get it while he can.
Lightroom was originally designed for a professional photographer who imports a great many pictures and wants to quickly go through them, picking the photos he wants, and then retouch the images. The original Lightroom did this in a photojournalistic way. Unlike Photoshop where you can modify photos, Lightroom was good for things like changing white balance, color levels, dodge and burn, etc. Essentially the idea is that Lightroom is for a pro or semi-pro photographer who wants to go through a lot of photos, pick the right shots and adjust colors.