Can anyone vouch for a user called DanDome please?

This appears to be the first mention of that user on the GOG forums.
Have him post here before any trades.

Ask them to reply to your trade-post here, as per rule #6 in the OP. If they stall posing seemingly innocent or naive excuses, or refuse, I'd not go through with any deal.

Also, watch out for too good deals, and any requests/demands to test if your Steam keys are valid before them purchasing anything for you here.

That account is created in June 2016.
May be one of scammer alt .
Proceed with caution.
Ask him to send keys first since you have older joining date.

Edit: Got the Warhammer games. Thanks for the trade BROKENSAINT.

Many thanks to those who gave me advice. It is my first time offering a trade and your advice is very much appreciated.

If they won't post here, it's most likely the Nes400 scammer.

Thank you, cmh5 for an amazing trade.

That's an advice you should't give in this forum, because it violates GOG's User Agreement (see GOG.com User Agreement - 6.6)
You might want to edit your post, or GOG considers you uncool ;-P

I have :

(GOG)
-Shadowrun DragonFall: Director's Cut

(Steam)
-Velocibox
-Super Motherload
-Heroes of Legionwood
-Megabyte Punch
-Pixel Piracy
-Velocity Ultra
-Qora

I want:

(Steam or GOG)
-Guild of Dungeoneering:Deluxe Edition
-Enter the Gungeon
-Stories: The Path of Destinies
-Shovel Knight
-Curious Expedition
-Risk of Rain
-Dex

Many thanks.

I have Risk of Rain (Steam)

Wich one do you want for it?
Since I'm the newest member I will send it first.
Send me a message in chat.

Want
any of the Dungeon 2 DLC's (GOG)
Dex (GOG) [Preferable want]

HAVE (steam)
Knights of Pen and Paper
SpaceCom
Retro City Rampage
Luna's wandering stars
Outlast
Baseball Stars 2
Metal Slug 2
Unmechanical
Steam Cards [FWIW]

FWIW you can see my card list at https://www.gog.com/forum/general/the_steam_trading_cards_topic

I missed the sale on KERBAL SPACE PROGRAM and I'm hoping somebody has an extra copy (gog.com code only)

I have the following gog.com codes availabele:
CONSORTIUM: MASTER EDITION, THE
WITCHER: ENHANCED EDITION, THE
WITCHER 2: ASSASSINS OF KINGS, THE - ENHANCED EDITION
AGE OF WONDERS
TEMPLE OF ELEMENTAL EVIL, THE
DON'T STARVE
EXPEDITIONS: CONQUISTADOR