well i would suggest go for it... most people that i taught has already have their N3DS downgraded... some are still in progress of downgrading... none of them got bricked/semibricked.. so why dont give it a try (as long as you follow the steps right :)
nope its not.. you supported the game developer.. so that a good thing :)
i got also the gamecart for MHX but i have a cfw N3ds so i'll just keep it and enjoy playing english translated MHX :)
have you tried to:
1.) remove the SD card and battery then press power button for about 60 secs then place it back again
2.) then try to recover 3ds by: L R Up A (Left Shoulder Button, Right Shoulder Button, Up on the D-pad, and A) while powering it on
hope this works and good thing you got...
i tried emuNAND9 as well but i causes performance issues with my sd card.. i would suggest use gateway to make an emunand and then proceed with cakes, that went well with me :)
if you can still wait a little longer... there is a chance that you can get a more stable downgrade tool... i would suggest skip buying the sky3ds cart you can downgrade like what i did too to my N3DS :)