Like you I too just run the old Firefox. I suppose there's security issues, but maybe I just don't let that kind of thing bother me until I feel I am actualy affected by it. Some posters here are really fanatic about security and would be horrified at even the slightest security hole. I run widgets that tell me about traffic on my network and I haven't seen anything about my computer behavior or network traffic that suggests I am being affected (I don't see my files being copied off gigabytes at a time, or constant network traffic suggesting my computer is being used as a phishing server). I also drive an old car with no antilock brakes or airbags. A safety freak would be horrified without those. I just drive carefully and accept that slightly increased risk level.
At some stage of course, we will just find our old FF refusing to respond to coding on some pages, but even that I haven't observed yet.
Others have gone over to using TenFourFox. I tried it but its default settings are to avoid many of the security issues by simply disabling a bunch of plugins I use regularly. I think there is some way to turn this off but I haven't gotten around to testing it again that way.
Well, not actually widgets. I use iStat menu (an older, free version) and occasionally run Little Snitch in demo mode (until I can afford it full time).
iStat displays an item in the menubar showing how much incoming and outgoing traffic I have. If I'm just sitting here typing (which should involve no network traffic at all) and were to see a sudden burst of traffic then I'd get suspicious (never seen anything I wasn't expecting so far). Normal traffic for web browing is a few KB/s. Internet radio is 16KB/s. I pay for a maximum of 113 KB/s and if I were to see that outgoing I would know major file transfer was taking place. I usually only see that incoming and when I am downloading a file.
Little Snitch reports and stops traffic to sites as configured. Again, it usually mostly catches things I am expecting such as an item automatically checking a site for updates.
On the Firefox side I run NoScript, adblock plus, ghostery.
You can download TenFourFoxG5 from here:
Now for the intersting bit: TenFourFox, like Firefox, does not support most plug-ins. Unless you are prone to headaches (in which case don't) you can read about that here:
But there is a workaround!
Open TenFourFox and type in the address bar: about:config (no spaces) and click return. This gives you a warning that it might harm the application. Ignore that and click on 'I'll be careful, I promise' and you get the config file that you can edit - with great care.
Look/search (scroll down) for: tenfourfox.plugins.enabled
Set it to true. (Double click it to toggle it)
Now close TenFourFox, open it again, and Flash will now work, as it now uses the plug-ins that Safari has stored.
I am using Flash 10.1.102.64 in TenFourFox and it works just fine.