I am not sure of the need for consistent naming as you have it there. Most of the DS sections were born out of demand (homebrew and ROM hacks used to be one) or how things shook out -- there are custom firmwares for the DS but most people only use one, if they use one at all, and there is basically nothing to configure on it. DS wifi is pretty much dead at this point, save for things like
http://gbatemp.net/threads/save-nin...e-online-servers-for-ds-and-wii-games.362717/
On the other hand I am a fan of navigation similar to that (if I am floating around a Japanese forum and I figure out nds ゲームエミュレータ is dealing with nds emulation then even if I can not be bothered to properly decode some kana then gba ゲームエミュレータ is probably worth looking at. Ignoring that, some of the sections might benefit from a name rejig but I am still not convinced a harmonisation is the way forward.
I am not sure how the and, & situation came about. Probably from a longer section elsewhere in the forum. Not sure if it needs resolving or how to.
On prefixes and tags. It would be lovely if they were used. We had something similar called tags, though they functioned in pretty similar ways rather than the more blog style thing you might be envisioning, before the move to xenforo however long ago that was. The staff and a few members used them pretty extensively but... well you know how it would be nice if people loaded the dishwasher rather than leaving things on the side? I would heavily oppose a move to make it mandatory, to say nothing of having to reclassify the years of existing stuff (just splitting the computer section up a few months back and moving threads around was a pain, I can not imagine this will be easier). If you are running a small forum or a blog with dedicated authors/fiddlers then prefixes/tags are great but not for a large general forum with members of the public posting.
On the prefix colours thing then looking at the css it looks pretty similar where it can be (the .prefix.prefixSilver having a changed font colour for readability reasons), however this is a making things look pretty situation so I will leave it. Though I did change it to Fixed and black text and it looked OK.