Where the bond is concerned I certainly wouldn't use it as a deductible from course costs / loan repayments in any future financial planning. It's an incredibly clever way of saving costs for all parties and also a way for L3/CTS to ensure your performance. If you're going for the easyJet MPL then do so presuming you're going to be paying the full sum and then forget about the bond for now. It shouldn't really be a deciding factor. At the request of the moderators here I shall not post a link, but those aware of my blog will find an article there related to it.
In respect of the pre-Dibden tests - if they're even being employed this round - then they're called Cut-E. Employers can pick and choose a combination of tests so who knows what battery you'll get this time. Dibden tests are PILAPT. Again, lots is documented on these on several cadet blogs and latestpilotjobs.com, pilotaptitudetest.com, and SkyTest will provide an idea as to what to expect.
Living expenses wise, budget a few thousand for that. Despite how much we moan about Britain at least we've the infrastructure. It certainly isn't cheap to live in New Zealand where easyJet prefer you be sent.