It is probably because your computer does not have enough RAM (random access memory). The more RAM you have the more things you can do at once on your computer. If you have an older computer it usually won't have a lot of RAM so you may want to invest in more. It may also be a virus that slows down your computer, try running a virus scanner to try to get rid of any possible viruses.
Runescape should work perfectly fine on mozilla. I use it aswell.
Try reinstalling Java, Flash or wateva and retry playing Runescape.
you cant
Make sure you have the latest version of JRE installed. If not, visit: http://java.com/en/download/ If this still doesn't seem to work for you, try running the website using Mozilla Firefox. Mozilla Firefox can be downloaded for free from here: www.mozilla.com
You may not have the requirements needed to play runescape, try updating your java and if that does not work, then try using a different browser all together eg. Mozilla or Safari.
You can no longer play Runescape 2, all RS2 accounts were automatically converted into Runescape 3 accounts. In the game options you may however select to play in "legacy mode," which allows you to enjoy the game with a familiar interface.
Make sure you have the latest Java downloaded, if that's not the case try playing runescape on a different internet browser, like Mozilla.
This "Advanced Program" you may be on about, may be the Runescape Client, which enables players to play it without going on IE or Mozilla, it allows them to play from the Desktop.
You cant.
You may need to update your java, if that's not the case, try using a different browser altogether like Mozilla or Safari.
you cant
You cant.
you cant
You cant but you can attack it.