Firefox/Safari were constantly crashing- now have to force-quit all other apps on MBP..

Question

I really hope someone can help me. I've been having an issue with apps on my MBP crashing for like 9 months and it's getting worse and I'm losing my mind! It started with Firefox. Everything will be going along fine, and then suddenly I'll try to scroll down on a web page or click a link or really do anything and there will be a rainbow scrolly wheel delay that can last anywhere from 5-20 seconds.  I'll tolerate it for a little while, but eventually I can't take it anymore and try to shut down Firefox, which I can only do with a force quit.  Sometimes the delay is accompanied by a crazy increase in CPU which triggers the fans, but sometimes it's not.  It usually happens when I have multiple tabs open.  A while back I tried removing all my Firefox add-ons and plug-ins and whatnots (including Flash and Java), to no avail.  So I broke down and started using Safari...and the same thing happened. Went back to FF and keep upgrading to the newest versions, but the problem hasn't gone away.
Then, a couple of months ago, a few of my other "big" apps (i.e. iTunes and Adobe Reader) started experiencing similar delay issues.  No scrolly wheel appears on these, but everything  just takes forever and the only way to close these apps is to force quit.  Over the past month or so, the issue has  spread to my MS Office apps.  For these, the delay is largely contained to opening and closing new docs/presentations, but I have to force quit to close them too.
In February, I decided to move to Lion, but changed my mind when I read that people were still having issues with decreased speed and spotty internet connectivity.  I was afraid to do anything that might make things worse.
My MBP is turning 5 this month. I wouldn't be entirely surprised to hear that she's just experiencing the effects of old-age (after all, 5 years is  2X longer than my old PC lasted), but I've been unemployed for well over 2 years and am not exactly itching to get a new computer right now if I don't have to.  I did upgrade the hard drive about a year ago, but things were fine for the first few months after that.  Maybe that wouldn't create problems right away, though. I don't know.  Anyway, I'm running OS 10.6.8, Firefox 13, iTunes 10.6.1, Adobe Reader 10.1.3 and Office 2008.
I would be most grateful to anyone who can offer a potential home-repair solution (one which does not require mad IT skills), knows what the problem might be and/or how much it might cost to have it professionally diagnosed/repaired.  Depending on what it could cost to diagnose/fix it, it might not even pay to bother.
Thank you!!!

Answer 1

Mark,
Have you checked the Fonts folder found in Home/Library/Fonts folder if you have any fonts in there, try moving them to the trash but do not empty the bin.
Read Kurt Lang's ~ Font Management in Mac OS X
on required fonts, for apple applications.
This app is a goodie Font Finagler helps find & remove corrupt fonts.
Have you tried a test account so you can narrow done if this is isolated to your username account, or if it is system wide.
Disabling "troublemakers" doesn't always work, uninstalling can be more telling & what are they anyway the troublemakers you speak of?
What have you tried to troubleshoot?
http://docs.info.apple.com/article.html?artnum=25392
Do you use any internet cleaning apps to clean internet clutter?
OnyX Niel'sClearing caches with OnyX
Cache cleaning does help, but beyond empty the cache under Safari.
Checked the console.log & system.log for any clues?
Lastly are you very committed to running 10.4.7? (If your spex are correct)
if you decide to update see Macmaps , yes this hanging of apps. should be tended
first.
Eme '~[ )♥♪