It may look like the normal 3DS home screen, but if you have the RX prefix on your version number, then you're booting into emuNAND. Depending on which version of rxTools you're using, you'll need to hold either the R or L button while rxTools is booting to get the rxTools menu.
Yes on the CFW part. Smea announced a downgrade method for 10.3 and below, which will allow you to downgrade to 9.2 and install CFW. HomeMenuHax doesn't have full control. It's a userland exploit; you need an ARM9 kernel exploit to gain full control. ARM11 is easier to access than ARM9 and that will give you enough permissions to downgrade. HomeMenuHax on its own has neither ARM11 nor ARM9 kernel access.
You'll need to set up a CFW to install a Cubic Ninja cia on sysNAND. Once you've got Cubic Ninja installed on sysNAND you can use it to access the Gateway menu. Follow
this guide up to the point where you install the cia manager. From there install Cubic Ninja and use Cubic Ninja to access the Gateway menu.