also matey, I am pretty sure that sellers have to tick a special box somewhere for the answers to show up "down there". (I have NFI where it is and as such I obviously don't use it LOL) so it might not be that the seller doesn't answer questions, only that they don't display them.
As for communication - whilst it is frustrating, eBay isn't like a regular store where people are on hand to answer your questions at all times. So you really do need to give people a bit of time to answer the questions, eh? They may even be like yourself and work away from home or have other committments which mean they can't get to the computer every day, or the same time each day.
As for payment, technically you have up to 8 days to make payment. The seller may open an UID after 4 days and you then have a further 4 days to pay before any action can be taken against you,
Now this may upset the seller, and in all fairness, I don't think that you should bid if you can't meet their specified requirements or are able to enter into a different agreement with them - even if it is their fault cos they don't reply to you.
At the very least, message them if they haven't contacted you before you have to leave, tell them the situation and let them know that should your bid place you as the winner that you will make payment on ++++ (whatever date you return) Keep in mind, they may cancel your bid if they don't agree with that though.
Personally, unless you really want the item, if they don't respond in the timeframe conducive to your needs (ie before you have to leave) I'd move on and find the item elsewhere. Whilst they can't make you pay more quickly than I wrote above and once the auction does finish with you as the winning bidder, the law says they do have to honour the sale even after the 8 days eBay allows, they have said when they want to be paid, so if you can't meet that, it's probably not the right thing to do to bid anyway.
Best of luck with it all,
Some people can go their whole lives and never really live for a single minute.
