Change remote mapping after flashing tot NAND

I was flashing multiple MXQ's with custom remote.conf's and must have messed up somewhere. After I flashed one of the boxes all buttons worked except volume up and down, which are very important when watching in bed while the girlfriend's sleeping so I don't need the TV remote to control volume.

I connected with filezilla and had a look in the .config folder on the NAND of the box, but couldn't find the remote.conf there. Is it in another folder or do I have to start over with a fresh SD card (with the right remote.conf) and install to NAND?

Maybe a little off-topic, but since I have unused buttons on my remote, can I map one to a shortcut that brings up the subtitle sync screen?

I found the keymap editor which lets me define my volume controls and also the subtitle sync menu (without the osd buttons which were always in front of the subs when trying to sync lol), but I would also like to map a key to take me to the subtitle menu, where you can select different providers and subs. I don't find this option in the keymap editor, is it possible through a custom command in the remote.conf for example?