Yes, that sums up the difference very nicely I think.
No, I don’t think so. The possibility of circumscriptive multilocation would apply to things like the ‘bilocation’ reported of some Saints (like Padre Pio), where the individual is (allegedly) physically present - in exactly the same mode with his own proper accidents/appearance - in more than one location at one time. I don’t know the texts you’re referring to, but I don’t think Scotus or anybody else would have been suggesting this kind of thing could apply to the Eucharist.
You open up some very fundamental metaphysical issues with this kind of question. But no; God’s omnipresence does not mean that he is identical to everything that he is present to, although all of creation does reflect/express, in millions of different ways, the infinite nature of the creator. But the being of Jesus, who is God and man, means that the infinite nature has been joined to a finite nature, and with that finite nature comes a proper location and proper accidental appearances which are also finite, that is, not omnipresent - and these finite attributes that are taken on through the incarnation do not pertain to the divine nature as such, although they have been hypostatically joined to it in the person of Christ.
God bless.
