You should replace
Sleep Caradhras with
Grown Suddenly Tall.
Eomer TMOR is fine, but I always prefer Eomer SK simply so I can recycle some of those skirmish events.
Shadowfax seems like it might clog a bit, so an option might be replacing a copy with either
Rohirrim Shield or
Have Patience, both of which help with some healing. As far as
Trust Me as You Once Did, you would need to rework your fellowship to get those Gandalf signets, so although it might be helpful, it's probably more of a pain.
Trimming:
Hearken to Me is a great card, I love it, but with 37 cards in your fellowship, it becomes more of a copy of
Herugrim. I would cut it, especially if you've designed the deck to be able to sacrifice Theoden.
Trim off a Gandalf copy, 4 is a bit much.
Narya could possibly go, I've never used it, so I'm not sure how it's worked for you.
Overall, this is an excellent Rohan deck, I've been trying to perfect mine for a long time and this gives me lots of ideas.