How would you go about remaking Ruby/Sapphire/Emerald

I would follow this up by either removing Prism Scale (Gen V held item used to evolve Feebas since Contests didn't exist), or adding a similar item for Sylveon. I'd go with the first one because its evolution method made sense and was pretty cool in terms of getting players to experience content they wouldn't otherwise do so for.

So agree, the whole trading concept was stupid imo.