Hi there,
I know you posted a while ago but I've been thinking about financial matters myself recently. I, too, am fully funded which is great but i've also got a number of years research experience under my belt and although grateful for the funding, it doesn't compare to full - time employment. Nevertheless, I also d a PT RA job as I think its more relevant than a pub job to CV, it 'forces' me to organise my time and pays not bad too! however, it is difficult to juggle depending on where you are in your PhD. Someone I know does some tutoring work over the internet and works with students with learning needs and she always seemed to manage.
I've also heard recently that some of the funding bodies will now start to fund PhD's for up to 4 years which finally should remove the stress associated with working and writing up - can't come soom enough as far as I'm concerned. I also think there should be equal levels of funding. In my department there is wide variation and those on the 'best' funding grants appear to be invested in more than those who are not - in my humble opinion. It's hard enough to do a PhD without all these antecedent issues too. Good luck with juggling finances-it is a creative challenge, that's for sure.