I remember doing something like this before. Was that novels? Anyway, I don't mind skimming a few stories and giving my impressions.
Hum. Writing off Worldcon this year is going to be tough. As I understand it, you want to earn more than you deduct, because otherwise you are entered into the 'loss' section of being a business owner, which makes a lot of hassles for you. So, you'd not only have to make some cash, you'd have to make enough to cover the laptop and Worlcon--so we're talking several grand here.
If you want that much by the end of the year, it's going to take some serious professional sales--markets paying 10+ cents a word. Not impossible, but those markets can have long review times, and can be rather finicky. That means you'll want to send off five or so short stories before the end of June, I'd say.
That means, fix up ALL five stories and make them as good as you can.
Also, for the laptop, you can always deduct that on a 'depreciation' scale instead of an 'all at once' scale. That's what I chose to do, since it gives me a small deduction every year instead of one big one.
