Hi Fred, and thanks for your suggestions, that fixed it!
On my pad I did find that the angry birds apk's to delete were actually in
/data/app/ and not in
/system/app/
thanks again! my son will be very pleased that he can play all 4 of the angry birds games again
Edit: I should mention that the app "Zoodles" is great for locking the pad down, as well as customising the experience to the age of the child. Check it out if you have kids
MXPlayer works well for all the videos I've tried and I'm still trying out different browsers. Shame no Chrome on pre-ICS but this ROM is great once you've got it customised a bit