It’ll be interesting to see how it plays out, if instances with downvoting disabled become popular
Personally I think downvoting is important, it’s like micro-moderation, in a democratic fashion. Sure it doesn’t always work out well, but it can be good for keeping spam and malicious posts at the bottom.
If a community is too specific then it won’t gain traction. I think definitely keep it as general as you can, like just a graphic design community (if there isn’t already one)