NTR CFW 2 (after it adds O3DS support), homebrew that isn't available as cia (seeing how rx doesn't support 3ds/csu, so cia only is a bit restrictive).Why would you need Ninjhax when you have a CFW?
I don't think it should affect the battery if you don't have a ROM loaded, though. But don't quote me on that.Nah, signature checks are patched on official rxTools 2.5.2. He means disabled in that signature checks are ignored, thus allowing unsigned cias to be installed and played.
The main advantage would be not needing your DRM cartridge in the back of your 3DS, which will improve your battery usage.