- Is the Encounter Type for daycare eggs 'Gift Pokemon (Non-Mystery Gift)'?
Yes
- Is there a way to find out which IVs are inherited from the parents?
No, half are from parents (inheritance determined by PIDRNG seed), half are from the MTRNG seed.
- If there is/isn't, would it be better to let the parents hold an everstone, power items or hold nothing at all?
Everstone
- How do power items and everstone affect the PIDRNG?
They force it to do something else, don't use them as we can't predict them.
- How do I search which seed/frame I hit when do not get the result I want?
Find the inheritance pattern depending on how many saves/chatots you do. Then you can find how many you need to hit your target frame. Just like every other type of standard abuse, you have to calibrate to find the initial frame.