As to the first, again the timeframe of ebay means sometimes you've just got to throw a bid on; and you're forgetting distance, if it was easy for him to go see it, I'm sure RobinBHM would have, he's not an silly person.
To the second, again ebay timeframes, blah blah etc etc. - Asking questions IS NOT "cold feet", just prudent when dealing with ebay sellers. Worst case if the seller isnt forthcoming he doesnt pay and the seller has to relist it - and I would also say to RobinBHM if the seller tries to get a "non payer" mark against you I would appel on the grounds the seller ignored your attempts to communicate.
There are MULTIPLE INHERENT RISKS with selling on a platform like ebay and ANYONE who's ever sold on it will know that, and this is one of them, also as you pointed out a seller can now offer to the second bidder (which they couldn't before some years back), so the risk now is even smaller than it was before - but "keeping the second bidder sweet" just how would you do that? Tell them the winner is pulling out, without proof to the fact (only your paranoid assumptions) and then said second bidder gets thier hopes up, only to be dashed when RobinBHM makes good?
Worst case if RobinBHM does pull out because the answers he gets are not to his liking and feels bad he can offer to paypal gift the listing fees etc etc. If the guy doesnt respond, then as a seller it's his own fault and he can eat the fees himself and hopefully learn a lesson.
Get a grip people, this is EBAY not bloody Sothebys! Sheesh!
If I was spending money I couldn't afford to loose I'd either not bid on the item (and look out for something nearer at a later date) or make the effort to go and look before making the bid. For something at a throw away price, no I wouldn't care, I'd place the bid and keep my fingers crossed.
If I was interested in something I would ask my questions first. If the seller was selling something costing pennies I can appreciate that they may be inundated with questions and be unresponsive. For a capital cost item, and I appreciate that everyone has a different reference point , as a seller, I would make a more than reasonable effort to answer a potential buyers question. I see a bit of presale customer service as a method of increasing the bids on an item, unless obviously, if its a buy it now. If a seller isn't answering my questions, as a buyer, I would think twice about placing a bid - especially if its a lot of money.
If I was selling items on an auction site, and I do so from time to time, alarm bells would start to ring in my head if somebody who has won the auction starts asking questions that should really have been asked before placing a bid. I would certainly start to think about second bidders and keep them in my back pocket.