Max out the system ram on your laptop if you have not already done so. Use the system monitor utility to check out the baseline activity, that is, to make sure there are no other programs running at the same time that you play your games. Viruses can tie up valuable system resources to slow things down a lot. Run an anti-virus and update your windows on a regular basis.
No, you can not. Most laptop video cards are built into the motherboard.
Some newer laptops or larger ones have video cards as an expansion but the form and shape of them are still customized, and you'll be really hard pressed to find an upgrade for a particular motherboard.