Is this a scam??

Im a new in the trading community. Start like about a week ago.
I got trade offer from a trader. He then give me a link:
"how to avoid scam trade" - http://steamcommunity.com/sharedfiles/filedetails/?id=687540851

.After reading through this guide. The trade tell me he want to use middleman service to check whether my skin is safe or not(dupe) item. List of middleman is in the guide. There are 5 middleman in the guide but he told me to try to add the first 3 middleman. I thought it was legit.

1st middleman didnt reply.(got middleman tag in steamrep)
2nd middleman didnt do the service anymore (also got donator tag in steamrep)
3rd middleman response to me.(He didnt have any tag in steamrep when i check it however there are a picture in his profile showing that he has a middleman tag in steamrep.)(name Rabbit[SR+] Database) - suspicious

What i notice from here is that the guide was edited exactly the same day when the trader want to trade with me 25/7/2016 - suspicious

I did try to message the 3rd middleman whether i need to send him the item or not and he said i dont need to.
So we both continue the trade and he invite me to a group chat along with the middleman. The middleman then send a link :
"SteamDB Item Verification" guide - http://steamcommunity.com/sharedfiles/filedetails/?id=730475343 .

In this guide it seems that i need to send my item to the middleman. Link of his trade url is in the guide. Then i ask him again whether i need to accept the trade in steamguard. He say yes eventhough just now he said no need. -very suspicious.
Thats when i cancel the trade and both of them saying that im a troller and they are going to report me to make me get trade ban. Both of them unfriend me.

Ok so what i notice again is that this so called trading guide have been created under a game called Battlestick(Why u dont create the guide under csgo??) - very suspicious.
So from this what i thought is the middleman + trader + guide creator is the same person.( Scammer)

http://steamcommunity.com/id/SR112592695454 - bibanator(german youtuber) impersonator i guess / the trader.
I know he got trade ban and i have ask him why he got ban. He saying that he buy dupe item and that why he got ban. His inventory is full of keys (Rip Keys) but the account that got ban is only for storing keys and he got other account as the skin storage account(link to the account is in the scammer profile).

The guide creator
http://steamcommunity.com/profiles/76561198106777812
The middleman named Rabbit[SR+] Database
http://steamcommunity.com/id/SR02312345446777411
The scammer i guess?? aka bibanator impersonator (bibanator is a german youtuber based on google)
http://steamcommunity.com/id/SR112592695454

and how can i see back the chat history so that i can screenshot all the chat i do with the scammer. Teach me.

Please enlighten me if what i did was right or wrong as im new to this trading things.
Im the ✿✿✿✿✿✿
I hope u read this scammer.

Cant use retart word ?