The editor is still private, who originally gave me the editor asked for keeping it private (which means given to thrusted people only). Just prove your skill and especially care about quality.
2.5 Editor is 'private', maybe Koden can help you to convert the map 
somethings in 2.8 aren't avaliabe in 2.5 resources and the file names are different, that's where you have to look while converting your map, I mean, remove resources that only exist in 2.8, find in what 2.5 packages some resources are in and then find how to map with 2.8 ED to 2.5, ex:use UTPT to look into the 2.5 pakages, when u found what your're looking for, copy the 2.8 file, name it as the 2.5 file and then use that one in the 2.8 editor, I made a simple/noob map with 2.8 editor and then converted it to 2.5 with Eliz converter, worked fine 
sry for any language error or if the text is confuse, it's 5 AM here 
http://aao25.com/maap/2-8-map-converting/45/
http://aao25.com/maap/2-5-map-made-with-2-8-editor/
I think i've already wrote this somewhere in this forum...anyway, packages starting with a single-letter with no digit in front of should be fine for converting your map with Eliz tool without much hassle. Avoid using AI (bots), 2.8.5 one can't be ported in 2.5 and anyway even the 2.5 counterpart is rather useless.
Btw, if you look at your sound, static mesh and texture folder you'll notice you have a s-285, a m-285 and a t-285...a few bits of the 2.8.5 materials ported, if you need them (and before you ask, you can't port all of them, it's a mess).
It is true that it is rather disturbing conversion 2.8.5> 2.5. Software and must be converted.
Editor for 2.5, I think the version is private to avoid mass distrubution. So mappers Reserved elite or those showing devotion?
Also, remember that it is the community that makes to live 2.5, then it will anytime soon blockages for the creation, the community will be less map.
You see? Of course, this is my opinion, and I hope not to attract the wrath of the moderators
I always do or bring a little something for the games I liked (level design, texturing, modeling) ex: NWN 1 and 2, dod, dod source
I do not know if it is possible that a benevolent soul can deliver packages of conversion, or the dev team leaves the editor out of his safe
Have you taken a look at the server list? Barely a handful of custom maps get actually played every day (and by a tiny amount of players). Custom maps are worthy, but let's not exhaggerate how much they're worth to the game itself (or rather to the players). I would love to see em played but they aren't, really.
You used to create maps/levels for NWN1? That's cool, i pretty much started there aswell.