Aurabesh is a font you can download online, it's a real font/letterhead, not made up by Lucas for the SW universe... It's pretty easy to find, just do a google search and you can download it to put it into MS Word and type crud up in the Star Wars ffont....
It's seen in the films a number of places including the Control panel of the Impy Officer who's directing the Shuttle Tydirum in during ROTJ. It's in the prequals too and some things in ANH were altered for the DVD actually to nix "english" lettering and numbering to be replaced by Aurabesh...
CIS and GAR were covered well enough.

As far as weathering goes... People are going to give their honest opinions, which is as it should be, and while I can understand if you're not for it yourself Clone Hunter it's still something a lot of people like...
Does the Republic and Empire military organizations have cleaning specs for their vehicle crews? Undoubtebly, but as we see in ESB the AT-AT's are pretty grimey and not from action on Hoth... The AT-TE's aren't pretty when they're dropped into combat on Geonosis either, and Gunships are battle scarred as they just fly around Coruscant's pretty skyways.
The "lived in look" is important for the Star Wars universe...
more to the point though, If you peruse some of the top modeling/hobby sites and things you'll notice that weathering brings out detail... Some of it's just to show shadow and depth, it just depends how you weather... Some people go overboard, but some people can get it just right. Definitely worth checking out model websites to see what I'm talking about.
It's kind of the difference between looking at a model of a 2006 Ford Mustang, and a model of an Abraham's Tank just prior to being sent to war... The Mustang's gonna look all polished and new. The Abraham's is going to look dull, it's gonna show shadow, you're gonna see panel lines clearly for hatches or things like that... It won't look dirty, or battle damaged, but it'll show "things" better than the polished smooth Mustang would.
Kinda hard to explain really I guess...
Anyway, if you're not into weathering that's fine too, and you just don't of course and nobody's going to think less of you or the work for it. But at the same time people who do like weathering will either look at that as a negative on the custom or they'll just look at it as a personal preference, but either way they're gonna say it's something they think differently on but it's not a big deal either way really either.