The trick here seems to be how many pieces of fish you'll need to bread and cook. Is it 8 or 80? Assuming it's a reasonable number, here's what I'd do:
1. Cook the lasagna, this takes the longest
2. Near the end of the lasagna cook time, make your kielbasa and pierogi
3. Bread your fish and set on a wire rack as the lasagna finishes. I've actually found they fry better if you let them sit for a few minutes before frying.
4. Take the lasagna out of the oven and cover with foil. This should be good for 15 minutes at least.
5. Turn off the oven, put your kielbasa and pierogi on a baking sheet and store them in the still warm oven.
6. Fry the fish
Again, assuming you aren't frying 100 pieces of fish, everything should still be warm when the fish is done. The only caveat is I've never made pierogi, so don't consider myself knowledgeable on that item.
My other recommendation would be to find yourself a sous chef -- someone who can move the cooked dishes around at your direction while you make the fish. My wife is a great sous chef, but she's not for hire
.