I am having trouble with Shockwave Flash freezing and receiving Shockwave Flash is unresponsive errors.
This can be because of a slow or sporadic connection. It can also be because of a buggy script on the website you're visiting. It isn't necessarily due to a problem with your computer, though there may be a problem if your Flash issue is ongoing -- lasting more than a couple of weeks and happening on more than one website.
Also, I am receiving a lot of Mozilla Firefox is not responding errors.
This could be related to your problem with Flash. I've certainly had issues with Flash occasionally freezing Firefox.
Do I even need Shockwave?
Flash and Shockwave are used not only for videos and online games, but for other interactive content. Some websites are unusable without Flash.
If I look at my Firefox Add-Ons Manager I see "Shockwave Flash" listed under "Plugins." I think you can disable it from there. Or you can try using a Firefox Add-on that blocks Flash.
Once in a while I have problems looking at the GOG homepage, which uses Flash. Then after they update their homepage again, the GOG website works fine again. While it has a problem, I use NoScript to block Flash on the GOG website, and that keeps Firefox from freezing. However most people would find NoScript too complicated because you have to "train" it to some degree (e.g. -- allow this website, don't allow that one). There are other Firefox Add-Ons that block Flash that might be easier for you to work with.
You might also look at Adblock Plus if you're not already using it. Ads that use Flash may be poorly written and may even be malicious, and they aren't usually part of the website you're visiting.