I want to develop my writing skills to become more expert in order to be able to set my salary rates with Bitcoin.
You should develop your skill so that you can write better, not for getting paid in Bitcoin. No matter how bad or good you are, if the person doesn't want to pay you in bitcoin, you won't get paid in bitcoin. Developing your skills doesn't mean you will be getting paid in bitcoin. Look for freelancing platforms that are crypto oriented. Maybe post your gig their and you might get someone to hire you and get paid in crypto?
When our work is paid for in Bitcoin, it gives more satisfaction than being paid with fiat.
Why is that? Wouldn't you be already converting your btc to fiat sooner or later?