Not really on the 'ban list' side of things, but a couple suggestions. I'll probably add more later, but this is what I came up with at work.
1: Add a "Comparison" section to the general template, where the author compares his/her item to A) Canon Tech, B)Faction Tech, C)Company Tech and/or D)The Open Market. This would help cut redundant submissions as well as add a degree of realism to submissions, especially in the case of companies. I'll give examples.
I: A major faction does not need five different types of interceptors to function. Once a 'baseline' is established for almost any piece of faction tech there are only 3 reasons to make a new piece of faction tech, which are A)Modernization, for example when @[member="Zane Watts"] updated the entire republic fleet. B)Specialization, for example making an interceptor especially adept at tackling droid fighters, or C) To add logical and cultural 'flavor' to a faction, for example Hapes having Battle Dragons in the Republic instead of standard cruisers or Yuuzhan Vong having coral skippers instead of normal LotF starfighters.
II: For those submissions that aren't faction tech, you're essentially competing against the entire open market. If I'm starting a new company that makes guns I need to know what every other gun company makes, so I can do something different in one way or another. If I make a product and Blas-tech makes the same thing I'm not gonna make any money because A: They're a name brand and will naturally steal most of my customers and B: They have better resources, contracts, distribution etc, so chances are not only they're making the same thing, they're selling it cheaper than you can too.
2: More Dev Threads: At the very least, I believe every uniquely produced item should have a dev thread. Perhaps every minor production as well. If something is unique, or even 'special' it should have an IC reason to exist. I think it should be noted that a dev thread is not necessarily "I hit the heated metal with my hammer repeatedly to make a sword." If you're a bounty hunter who wants a cool sword why don't you go track down a bounty, be unsuccessful, and have your realize you need a wicked sword to be a better bounty hunter? Or be successful and cash out on a good paycheck? Need a fast ship? Lose a target because your ship wasn't fast enough. Or get shot down because you can't escape. There are tons of possibilities, and there is no real reason to dread a dev thread.
And on another dev thread note, I may be incorrect in this, but the way things currently look a major faction has to do a dev thread to build ships over 1K meters long, but companies do not. If a company, especially a non-canon company, is just starting out wouldn't they need some sort of assurance that they'd get paid before they make star destroyers? Like a contract of some sort for production? Admittedly this is more in the concerns of realism than balancing/helping the factory but it doesn't make sense to me that a newly made, Tier 3 company can mass-produce star destroyers, especially if they're around the same quality of a ship made by say, KDY, CEC, or Seinar, all companies that have literally been kings of their trades for millennia.
3:If a sort of 'help page' or 'directory' were made for submitted faction-less tech then that would probably help cut down on things a good bit. It wouldn't necessarily need to be anything fancy or detailing the submissions, merely say something like 'Freighters for Adventuring' 'For Heavy Weapons Enthusiasts' 'When it needs to Sniped' etc. and then put appropriate links under it. Admittedly, there is no guarantee it'll be utilized properly, and I question how often faction armories are examined, but if it stops five people from writing up five redundant submissions it's done it's job.