Well, it's not a million miles off...
I was aiming for:
"I learn other languages by translating English works into the other language". Except for the modifier order of ante toki, I'm fairly happy with that.
"Where (should I) write (such translations)?". I was close, I think. I'm not sure there's a better verb-modifier than tan here?
"In the forum named "musi", or in the forum named "ante toki"". This got lost, I think; can you suggest a better translation?
... also, given I figured out
that "ante toki" is basically "translation", I'm not sure why I needed to ask. Maybe because the forum summary is "Toki Pona content in other languages", which seems the wrong way around.
"If I wrote an English work in Toki Pona, would I be breaking copyright law?" - I got this completely wrong!
I think I like your version - "If I write using tp then I will break the laws of writing".
The question still stands, though. I think, technically, I would be; but practically is it frowned on?