Very nice work you've done, admin!
Some thing that need to be fixed for now:

• Translating the interface
• I get encoding errors when I follow reply links, that should be fixed while translating. The reply pages do not seem to indicate encoding in their html, try checking where in the script that html is generated.
• Images do not work, that seems to be a configuration error. Be careful when fixing that, for security reasons.

A suggestion:
NazoBBS is an Ayashii style Japanese board that allows the use of html tags for formatting; the most commonly used ones seem to be marquee tags, font tags, and svg tags. It also allows setting styles on the tags.
Other tags are allowed on NazoBBS, but they aren't as commonly used (or as safe to allow people to use...)
The users of NazoBBS have managed to pull off some very interesting effects using this tag freedom, marquee AA mostly. Users on Sageru (mainly me wwww) have done similar using the exploit there.
It would be nice if you allowed the use of some html tags on here as well, though within reason to avoid anything similar to Sageru's constant BEES. I'd love to post some moving AA tanks like on Nazo.