>>11849101There are only 11 IVs, 20 - 31 stay as they are, anything lower gets bumped up to 20 (the new 0). Stats are recalculated when a pokemon is migrated.
Hidden power only ranges from 60 - 70 Base Power.
You can leave a single charm with the DayCare couple. There's the Round and Shiny Charm and the new Potential Charm that passes down the HP type of a specific parent guaranteed.