This guide is a WIP- thank you to Mist for the info!
you can make a wish 7 times a day for any item that's in the game (search the item on SW, if it says "Searching for ..." it doesn't exist yet, if it says "Searching for ... (the item you searched for)" then it exists and you can wish for it) - there are no rarity limitations
it's recommended that you wish with a donation of 21+ nps to be safe if there are any minimums for a prize
prizes go out +/- 3 hours from reset time (12AM NST) and the daily reset for your 7 wishes is at 12AM NST
noah has stated that certain numbers may give a slightly higher chance, he didn't say which ones though