The big problem with my previous post was that I tried to keep things simple by not adding that the power was to be used with INVISIBILITY to in effect make invisibility selective (bypassing the fact that invisibility isn't resistible). This would make my first question not be answered by morph (it wouldn't be visible), and make more sense out of my second question (the illusion could only be used to mimic the actions of the character, although it could also be used as selective speech).
I don't really understand this. But perhaps if I break it down, we might get closer to what you're after.
Illusion, Invisibility (Concealment), and Morph are three separate powers with very different effects. (I don't know what "selective speech" has to do with any of this.)
Start with the EFFECT that you want to create.
If the character can't be seen (whether Resistible or not), go with Concealment.
If you want to make other people sense things that are not there, go with Illusion.
If you want to change your appearance (but still be visible) go with Morph.
Concealment (Invisibility) can be made Resistible (say by Will). Anyone making the Will check would see you. If you make it Selective, then you choose who sees you and who does not. If you make it Selective and not Resistible, then only those who you allow to see you will, and those without special Senses, have no chance of perceiving you.
Illusion and Morph cannot make you invisible as per their power effects. But as a Descriptor, you could, for example, always say that your Concealment has an Illusion descriptor.