I'd like to request a board for the discussion of current completed+unfinished maps, map ideas/level design and map version modifications. There's over 12k maps and we never talked about them and their potential. There's over 50 original Special Forces maps out there(+200 versions with tiny edits) and there is no place to talk about them. I'd like a board for both SC1 and SC2.

Welcome to SEN.
http://www.staredit.net/forum/37/
http://www.staredit.net/forum/10/
http://www.staredit.net/forum/11/
http://www.staredit.net/forum/8/

http://www.staredit.net/forum/37/
http://www.staredit.net/forum/20/

You'll find there's quite a bit of discussion for all of that in the forums in their appropriate sections.

Unless I find the appropriate thread for let's say Spellswords, Death Knights 3, Pirate Dyne, the 200 something Naruto maps, RP maps, diplomacy/civilization maps and then everyone becomees extra careful to not bump the threads, then the map production board front page will be overfilled, when that board is designated for the production of new maps.

I'd like a separate board for really old, but popular maps like Helm's Deep, any Lord of the Rings rpg map, defense, zombie maps, The Sims, Bound maps, racing maps, sniper maps, Crash rpg maps, unique maps, etc. It's a huge list and we have nowhere to store them.

As for the unfinished maps I meant alphas and betas, maps without endings like Zalirea and After Earth.
Ideas/modifications/editing for the current maps by third parties, not just theories and starting from scratch a reboot of the map like.
A board like that could also be useful for walkthroughs and requesting a specific niche of a map which nobody can find.

Unless the basic discussion of pin-pointed UMS maps isn't very productive for a technical innovative map community then I understand.

While you're correct that SEN has been created with production of maps in mind, rather than discussing existing ones, as a moderator of this site I can assure you that discussion threads are just as welcome. The Geneneral Starcraft Forum is the go-to place for anything StarCraft related (which maps definitely are) that doesn't really fit any other category.

That being said, I think it's great that you're so considerate and want to avoid spamming the wrong forum with your topics, but truth is, activity is so low these days that any (slightly relevant) activity is welcome activity. There literally is nothing to drown. So there really is nothing that should stop you from opening the desired topics, given that you put (at least a little) effort* into the opening posts.

*) just avoid making the same copy-pasta topic 50 times where you just replaced the map name. It should somehow spur genuine discussion. Instead you could create a single topic and list the maps. And if one of the maps attracts a good deal of discussion create a dedicated topic.

Looking forward to discuss your ideas!