I haven't had any of those problems myself. There could be a couple of causes. I don't think it's Flash because of that were out of date, the videos would never load up. You can try using a couple other browsers. This is just to determine if it's the main browser causing the issues or not. If it is, maybe try upgrading it and see if it works better, or switching to another.
If this isn't the issue, then another idea is to run a virus scan. Spyware and adware can slow the computer down, so try sweeping it and see if that helps. You can also try System Cleanup and see if clearing out the unwanted and unneeded files helps.
If none of that works, your laptop might just need a good cleaning. If you know anyone good with taking apart computers or have enough money to get it professionally done, you can have the laptop cleaned and dusted. There is also the chance that it just needs a new part. Depending on how old your laptop is, there might be something that needs replacing.
There is also the option of getting a new laptop or reinstalling the operating system, but I would not resort to this unless you absolutely have to. If your laptop continues to worsen and develops more problems, then I would recommend considering those options.
