Oh, yes, of course. Also, there is absolutely zero risk of bricking the device. There are some possibly interesting situations you could get yourself into with some of the more advanced features of emCORE that might be difficult to recover from - but you would need to make a conscious and deliberate effort to do things that in most cases the tools will (try to) prevent you from doing.
TL;DR: "Yes, there is, and no, you won't brick the device".
You may want to head over to the freemyipod project's
interactive installer guide for the iPod Classic. At the present point, there is no officially supported Rockbox bootloader. Keep in mind that there is no dual-boot support, and installation will wipe ALL data on the device.
[Saint]