I have a favorite way of framing this issue that might be useful in keeping this discussion from degenerating to epithets. Let me know what you think.
There are three things Kerygma, Dogma, and Devotion
Mary is almost zero in the kerygma, she is small but significant in the dogma, and she is large in devotion.
I think if Roman Catholics would adopt a scheme like this and stick to it and purge prayers and statements that confused it, they would win over many Protestants. The problem is that for the Protestant, they themselves have failed to keep all this straight. Thus Protestants are always uttering conflicting platitudes like "Unity in the essentials freedom in the non-essentials." And then splitting over nothing.
For the Roman Catholic part, it should not be a requirement to believe much about Mary except those things which are necessary to preserve a proper understanding of the incarnation (Ever Virgin, Theotokos). It should be a matter of pious opinion/devotion. You could win over a lot if you could adopt that.
The subtlety with which Mary has bee quietly inserted through the scriptures by name in the NT and by foreshadowing in the old is wonderful and not forced at all, seems almost as if God puts it there for those with ears to hear and doesn't want her forced on anyone.
Sounds like a good starting point to me, with the proviso that honoring Mary will always be mandatory in the Church, but being devoted to her in whatever degree, is optional, but highly recommended.
-Theo