Do they Japanese really have that many different imageboards?
Clones tend to exist around a larger website. The more popular the site the more numerous the clones. What's surprising is that there's a lot of Russian ones that I'm not sure what they're even based on or their origins
A lot of the Japanese ones aren't really clones of anything. It's just a particular type of website. And there are a lot of tiny ones you won't find in the lists. Sometimes it's just someone who sets up a personal image gallery and uses imageboard software to do it.
I say go for it. I've been considering doing something like that too, I just lack the technical knowhow to make it a reality.
I only ever knew of Futaba and Momizou. Honestly I never could get far into either of them. Even being able to read Japanese well enough didn't make them interesting discussion places at most times.
From my experience, most of the substantial discussion happens on 2ch. The content of the discussions itself is, of course, pretty hit or miss.