The Old Vicarage at Elkeskey is a lovely wedding venue.....the Cave Bar is fab!
The venue has a laid back bohemian vibe anxx do whilst the dress is nice, but I think it's a bit too casual for a wedding.
Maybe look at Ted Baker or Monsoon for something a bit less casual. A wrap kimono dress in silk would look good....still got that boho/casual vibe, but says you've made the effort to look casual! Maybe even a jumpsuit - solves the bare legs/no bare legs dilemma.
I'd go for a flat, wedge or block heel as well.