General questions Xubuntu 11.10

I have a couple of questions. I am completely new to Ubuntu and Xubuntu(i decided to install it because my computer is not too fast), I don't understand a lot of terminology and many things in Xubuntu frustrate the hell out of me. So if you can answer the questions, can you please do it in a simple fashion, describing each step. So i have a couple of questions:
1. I have a sound problem. Every time i switch between speakers and headphones the volume mutes automatically in the Alsa mixer. As well as people say It is really difficult to hear my voice via skype. As i understand many people have problems with Alsa mixer. But i couldn't understand how to fix those problems. Can anyone tell me how to fix it in a more simple words?
2. One time my audacious player stopped responding, but i couldn't find a way to force quit the program. It there a simple way to force quit applications in Xubuntu?
3. I get a very annoying bug - sometimes when i click on a drop down menu, the menu stays open while my left mouse button is still pressed, but when i release the button the menu disappears. In those cases i have to keep the button pressed, move the cursor to a option i want to choose, and when i release the button the options opens. But it is a bit annoying. is there a way to fix this bug?
Thank you very much.