Question 1: Can I run the games on a laptop with an intel i3 and no discrete graphics? Question 2: Is it okay to just pay a dollar or so to start, and then pay more if I actually enjoy the games?
2. I feel this is completely okay, you are not stealing from them because you cover the charges for your purchase and if you use steam for download you are not wasting their bandwidth.
All of the games are excellent so I bet you will enjoy at least two of them.
And as far as bandwidth goes, there is a Bittorrent download option that probably beats out the Steam servers anyway.