Hey there!
You can move your eggs any time. I scooped mine out as soon as I found them! They're very goopy and flop around on anything. Use a credit card or spatula to scrape them off whatever surface they're on. The goop is very thick and protects the eggs. They're very hardy so don't worry; in real life they're tossed around river currents and jostled all the time.
You should freeze the ones you don't want - put em in a bowl and pop in the freezer. That's a humane way to dispose of them.
I would say keep 50 eggs - the rate of death is high when they're in the egg stage so you'll probably end up with 10-15 eggs that make it to larval stage.
You can feed them once - twice a day; whatever is do-able. But probably not more; the bbs dies within hours and fouls the water do you gotta do a 70% water change after every feeding. Plus, they can only consume/digest so quickly.
Give them regular light; it encourages appetite and aids in proper growth.
I would suggest raising them together in a small white dish. This way you can see their development very clearly and detect anything amiss. With a white dish you can also spot any yucky junk on the bottom. A whole tank won't be necessary til they're quite bigger! A small dish will be adequate for the first 2-3 weeks I'd say.
Some forums suggest raising them separately while others say together. I've been raising mine together and it's gone off without a hitch; supposedly it teaches them to recognize each other from food!
Also, if you spot a spermatafore in the future I would encourage ya to suck it up with a siphon to prevent future eggs. They're quite time consuming to raise! Then you have to worry about them falling into irresponsible owners who will get bored or tired of taking care; or won't provide proper care at all!

I worry about the homes I'll find for my surprise batch.
The larvae don't need filter, heater, or bubblers. Just clean, fresh water, regular light, and daily feeding
Good luck!