yes
no it doesn't need steam
yes you have to have steam.
Yes
You can't they were conquered by the Ottomans already... You can play as the Ottoman Empire though
No
If your laptop has the required processing power, you can play Steam games on your laptop. Both my brother and I play Steam games on our laptops.
No, only if you want to play Duels of the Planeswalkers.
No, you cannot play Day of Defeat: Source without Steam. The game is tied to the Steam platform, which is required for installation, updates, and online multiplayer. Players need a valid Steam account to access and play the game.
Team Fortress 2 is Free-To-Play on PC, so you do not need any CD. You need the software Steam to install the game, though.
Yes the newest war-games need steam because to play online they must have a network where u can chat and play. PS3 have PS network, Xbox have xbox live but we have steam!
You don't need to enter your credit card info to get steam, or to play most of the "free-to-play" games. If you want to purchase a game or an in-game item through steam, you will have to provide them with your credit card info at that time.
You need half life if your want counter strike and Steam if you want to play online you can also buy it from Steam..