I can reply to all four of them with two words:
oh well!
I also change my oil using a factory filter, but I'm lucky enough to get the right size from my dealer. I just use a great big pair of adjustable pliers to loosen the old filter (I don't care if I bugger up the old one) and haven't bothered to change the drain plug washer. I installed the new filter no tighter than I could get it with my bare hands, and all has been well.
For as often as I will need to change the oil I'm just going to stick with the factory filters even if they cost a bit more. I suppose the only thing for you to do is make sure to ask for the filter by part number (not bike model) and then you'll be assured it will fit the bike as well as the tool.
Sorry about your bad luck, but don't let it get you down.
