No, you aren't.

Nope I am not worried in the least. Though most of my wins come from private giveaways with people I chat with daily.

May not be a surefire way to dispute, but you could use this site as evidence in the case of if they ban you due to receiving a gift from a stolen cc. Since it is random lots of who win and can in at least a small sense, prove you weren't part of the party who did the crime. Never been in that situation, so couldn't tell you if that would be sufficient enough.

people arent that bad...

That why steam support is here

They actually don't ban your account now, they revoke access to that particular game.

Why would someone with a stolen credit card use it for Steamgifts?

I dont get many stuff anyway so I aint worrying.But on the other hand I have bad luck so maybe when I win in giveaway that aint private I will get a gift that was bought from stolen credit card...ah well...piss.

I'm worried about receiving CD-key's (instead of Steam Gifts) via steamgifts.com due to the fact that if the gifter has the retail version, he/she can attempt to steal my account via posting a picture of said retail copy and claiming my account is theirs :(

Am I being paranoid?

Im not worried if people want to take ownership of my steam acc ... I have proof that account is mine, I have retail copy of Orange box, Saints row 2 and Left 4 dead 2 that I can easy show to them.

But that credit card stuff is kinda bad i guess :/

I have 3 physical cd keys that I could use to prove ownership of this account, and one of them was the game that this account was created with. Would I be safe from that kind of trick?

If you come to think about it, such problems are born because of human incompetence and weak system. The same shit as like if you would've won a prize in real life, say a toaster, and then a repo guy comes to pay you visit and says - "It has been stolen and then gifted to you. We're taking it back and in the meantime we're taking all you're kitchen stuff as well. Don't ask why.". The kitchen stuff stands for all legit games I own. But would anyone give a shit?

The cdkeys you have to worry about redeeming are box retail copies. They want a picture of the cd key with your signature and steam support number handwritten on the box next to the cd key. If you are to be worried about receiving a gift this is the one thing you should best not redeem. If you know the copy was from a digital distribution it's probably safe. (like the amd dirt3 giveaway, or humble bundle)

If you have 3 physical keys to prove and all were before the game in question you should be fine. Will just suck to lose your account for a couple weeks until you can prove your case to support. Also, as long the bulk of your account was purchased with cc or paypal you can provide that information and that counts the same as having a physical cd key. If you use both cc and credit card at least once that would be wise too because then you have more proof. I heard a story once where someone got a hold of a guys original game he created the account with and steam almost thought he was a liar even after providing cc.

However that being said, Steam Support asks for more than just a physical cd copy. You have to provide the account name. I would make sure that your displayed name that everyone sees is not the same as your account login. If you have never changed it I believe it will be. The also ask for all email addresses that have been associated with the account. So make sure the email located on steamgifts has not been associated with steam. Also make sure your real name is hidden. Those are the best and easiest ways to protect yourself. I was really worried for a while but not so much anymore.

All that being said, I have never seen anyone post on the forums on here about any problems with loosing an account. Let alone a game from a stolen cc. I know I would blow up the forums warning people if something happened to me.