We have some friends that live up that way that are pretty good with restaurant suggestions. In the past they have recommended:

For breakfast - Gourmet Gourmet, with outdoor seating.
For lunch, a local favorite is Cake Karibou, also with outdoor seating
For luch, Kellys Courtyard cafe -evidently highly rated on Trip Advisor.

They do not recommend a place called Merge.

The bike trails around the Omni Amelia Island Plantation Resort were nice. The resort rents bikes.

Will check on the kayaking thing. But I do remember the beaches around Amelia Island State Park being really nice. A bit south, though.