1. i think so, too. because the effect type of Io's Transmuter is permanent so it affect your whole turn, not just when you choose your die
thx for pointing this out, i previously thought that i cant do that
2. this one i'm not sure. but if i'm reading the card text as it is..
Instead of performing the actions indicated by your season die, you may choose one of the following actions..
If your season die grant you crystals, you may transmute during your turn.
then since the die doesnt actually grant you crystal (because of using Steadfast Die effect) then Io's Transmuter effect shouldnt work here. but i'm just guessing here too