Buying games when abroad

I can only help with your last question: clicky

edit: i was wrong apparently. ;_;

If I were you, I'd just buy something cheap to get the answer to first 2 questions :)

Oh, and afaik Steam dosen't convert wallet currencies, i.e. you can buy something with your CC, but not wallet funds.

Steam won't let you purchase from any store other than your own. So if you try and purchase a game, it'll the say the currency of your wallet doesn't match the store's currency. So what you need to do is add your country's store code to the URL. For example, I believe the Greek store should be http://store.steampowered.com/?cc=gr. Now you should be able to purchase games in Euros as usual.

When abroad I always buy using Steam Mobile App http://store.steampowered.com/mobile and never had any problems! and the prices were always in € (tested this while in UK and Croatia)

I always have my region prices on the Mobile app whenever I am abroad, and puchase witout any problems.

what does that have to do with being a broad? steam doesn't discriminate by gender :)

Hello @tragikos.
I was in the same situation some time ago while I was on a trip abroad, so I contacted Steam Support.

To cut a long story short, you cannot use Steam client to purchase when you're traveling abroad.
You must use your browser to make purchases by adding ?cc=<YOUR CC CODE> at the end.
Example: http://store.steampowered.com/?cc=<YOUR CC CODE> (i am not revealing your CC code here, you should know that already :p)
That way you are accessing your local store and all purchases will be made in your local currency.

If you don't use that browser url, your purchase(s) will be declined because the item price does not match your currency.
In other words, you cannot take advantage of the store prices in the country you're visiting.

Have fun and don't forget that... traveling reduces play time :p

EDIT: I have never used my smartphone to buy anything, I don't know if there is a way to configure the CC code there.