And certainly we should recognize that what is called "Q" need not all come from some single "source" or have been produced by a single writer. "Q" is just what is in common between Luke and Matthew and not in Mark. That material may well itself be the product of multiple revisions and alterations to a document that was later shared by the writers of Luke and Matthew.
In other words, from Mark some new version of the narrative was produced, and that version could have undergone any number of revisions by any number of editors before it was used by the writers of Matthew and Luke, so "Q" need not be some set of passages that come from a single source. Indeed the nature of Q, with its inclusion of the Temptation and various other scenes, indicates exactly this.
The material shared between Luke and Matthew itself is a product of multiple hands.
So I guess the question would be: Was Marcion one of those hands?
Certainly its possible, but maybe its not the best possible explanation. But its also important to make sure we have a solid understanding of Marcion's actual theology, because *Ev does include many of these passages about things like division, woes, etc. For example BeDuhn's *Ev has:
49“I came to throw a fire upon the earth, and I wish
that it were already kindled. 50I have a baptism with
which to be baptized, and what (more) do I wish if already
I have accomplished it? I have a cup to drink, and what (more)
do I wish if already I shall have filled it? 51Do you suppose
that I arrived to throw peace on the earth? Not at all, I am
telling you, but division. 53They will be divided, a father
against a son and a son against a father, a mother against
a daughter and a daughter against her mother, a mother-
in-law against a daughter-in-law and a daughter-in-law
against a mother-in-law.”
that it were already kindled. 50I have a baptism with
which to be baptized, and what (more) do I wish if already
I have accomplished it? I have a cup to drink, and what (more)
do I wish if already I shall have filled it? 51Do you suppose
that I arrived to throw peace on the earth? Not at all, I am
telling you, but division. 53They will be divided, a father
against a son and a son against a father, a mother against
a daughter and a daughter against her mother, a mother-
in-law against a daughter-in-law and a daughter-in-law
against a mother-in-law.”
Certainly Klinghardt and Vinzent have dealt with these passages, which are all a part of *Ev. I'll have to see what they say about them.