Regarding Gríma and Éowyn

[Evisse the Blue]

In that scene from TTT with Eowyn and Grima near Theodred's death bed, when he 'sweet talks' to her (using some of Aragorn's words from ROTK, as it has been already remarked on this forum), don't you get the impression that she is almost about to give in? But then she suddenly recovers, as if breaking a spell. Grima surely had a way with words, and Eowyn was, although very courageous and noble, sad and lonely. So, I think MovieEowyn might, in an alternate universe, given in to Grima, in a moment of weakness, and be very angsty about it afterwards.
But, without her consent, I don't think he would have been capable of overpowering her. Even if he is stronger than her (which I doubt), she knows how to fight better than he does.

3. In his own strange way, he really does love her, and he would not take her unwilling-- he really wants her to love him all on her own.

I don't think he ever harboured such hopes (if he did, his sense of reality is really low), nor do I think that he loved her for who she was. What he felt for her was simply lust (like Morgoth felt for Luthien). The baddies is Tolkien's world don't seem to be capable of feeling love.