Re the buffering problem, I have just read in a magazine that it could be caused by Firefox's Session Restore feature which is set to back up tabs every 10 - 15 seconds, especially if you have a lot of tabs open.
You can change this by typing
about:config
in the address bar (not search bar). When it opens, type
browser.sessionstore.interval
in the search box.
It will be set to 10,000 or 15,000. Double click to change the value to between 200,000 and 300,000. Save and close the tab.
It will do no harm to try, and you can always change it back.