I'm designing a Wood Elf Outlander Warlock (in D&D 5E) who only has one hand. This makes my arm near to useless. As an Outlander, I am proficient with a musical instrument, and have skill proficiency in Survival.
I have designed the character as a self-sufficient hunter, who uses everything from a kill: hides for clothes, meat for food, and bones as a carving medium.
What I would like to do is trade the musical instrument proficiency for a proficiency with a type of artisan's tools that would be used in carving bones into practical things I could use, or decorative items I could sell.
Would this trade-off be balanced?
Since a musical instrument is a potential spellcasting focus, I wasn't sure.
I've asked a follow-up question here: What kind of tools would be used to carve bone?