Anyone seem concerned about the warning that gabe and the team have put up about the steam forums being hacked?
I got an e-mail as well as a popup notice from the Steam client. Make sure you have your spam filters adjusted properly and that your settings in Steam are set accordingly.
But if a game has been properly installed it can be added to Steam without any hassle at all. Games bought through Steam are even easier to install. Steam's pretty convenient too since it can be used to buy games, has features that let you browse the net in-game and has the chat function. It's fine for me with online and offline games.
Also, I wouldn't say Valve is that powerful of a company. Steam is popular with PC gamers from what I can tell, but it's not like every computer in the world has it.
As for things like verification, it's necessary given how much piracy goes on.