Multiple tabs with flash or heavy js crash firefox

Question

Has been may years already that this keeps happening to me if i open around 150+ tabs (depends on the content of the tabs) or if i open 20+ tabs of youtube (might happen with other video platforms too but i haven't tested that) makes firefox crash after a brief amount of time. I've been using the same profile since mid 2012 but I do make clean new installs of firefox when a new whole version comes out. My pc hardware i think is more than suitable to be able to have that ammount of tabs open (12 GB RAM triple channel ddr3 1ghz intel i7 950 @ 3.07ghz 1024MB ATI AMD Radeon HD 6800 series on w7 x64).
I tried creating a new clean profile and opened 50 youtube tabs have all of them playing at the same time and even though at the start there was some kind of slowness for the firt 10 seconds then all was perfect and I tested it for like 5 mins and it didnt crash. Back with my profile I used the about:addons-memory to see fit here was any leak of memory from the addons but the addons consumption was really low. Although firefox itself with 150 tabs uses like between 900 and 1400mbs of memory. I've tried disabling all the add-ons and then enabling some to see if there was a conflictive add-on but i couldn't find whats causing the problem so i wanted to ask you guys if you could lend me a hand so i can finally can open as many tabs as i want without having to fear a crash.
Here are some crash reports
https://crash-stats.mozilla.com/report/index/ed544757-c6e5-4590-b2fa-ec3552140418
https://crash-stats.mozilla.com/report/index/e2256729-811b-4dcd-8d6a-6d0012140421
https://crash-stats.mozilla.com/report/index/a1648f3c-c5a4-41d9-b6fa-415cd2140430
https://crash-stats.mozilla.com/report/index/ec77ddb5-3be7-4268-a515-7195b2140425
I only have flash and java Plugins on and they are up to date.
Addon list:
Adblock
session administration
adblock element hider helper
autopager
bartab heavy
empty cache button
all tabs helper
anonymox
classic theme restorer
spanish Venezuelan dictionary
downloads window
mem chaser
menu icons plus
multiple tab handler
no script
places cleaner
restart aplication
roomy bookmarks
scriptish
self destructing cookies
site favicon in urlbar
snap links plus
Tab Granade
tabmix plus
text link
text area cache
wot
xmarks

Answer 1

I had/still have an issue with FF which is virtually identical to this (se https://support.mozilla.org/en-US/questions/988435?esab=a&s=&r=0&as=s).
Mostly on script/flash heavy pages (like YouTube, Google Play, Twitter, etc) with only a small number of tabs will result in nearlly 1-1.2GB RAM usage and eventually crash. Having looked through older crash reports here is a list of the most common problems (Note: I recently tried a fresh install so don't have the Crash Report Numbers for these anymore):
Crash Cause
js::ScriptSource::hasSourceData() x 3
NS_ABORT_OOM(unsigned int) x 5
gfxContext::PushClipsToDT(mozilla::gfx::DrawTarget*) x 10
js::AutoCompartment::AutoCompartment(js::ExclusiveContext*, JSObject*) x 7
Of Which
EXCEPTION_ACCESS_VIOLATION_READ x 21
EXCEPTION_BREAKPOINT x 5
I used to be able to run FF with almost 60+ Add-ons up to 60+ Tabs and still have it work more or less OK; obviously it could be rather sluggish and was eating into 1GB RAM or so, but it at least worked. Now I can barely run it with 53 Add-ons and less than 10 Tabs for around 30 mins to 1 hour before an inevitable crash.