A agree that you need to cut back on the shoes.
Are riding boots required to ride horses? Could you ride using the same boots you might wear for hiking? I like Ahnu Montaras for the support and stability. Along with a pair of graduated compression socks, I can be on my feet for 6+ hours a day with little or no discomfort. I never pack those boots in my bag. They are always on my feet in transit from one place to another, regardless of the mode of transportation. So if you could ride (both horses and bikes) in the same boots you walk and hike in, that would be a big savings in space and weight for your carry-on.
Those Sperry sneakers look cool, but I don't think they will supply the support you need for all that hiking and walking you list in your question. I also think you need to choose one pair of sandals, period. I know a lot of people really like the Keens, but if you were planning to wear them for hiking/walking keep in mind that much of the hiking terrain might not be paved and might have lots of little rocks. I've tried to walk my dog on our dirt roads in similar open sandals and there's no way to keep the sand, grit and little gravelly rocks out of them. The Keens I had were about 1 hour shoes, regardless of terrain.
I have only been one place where I thought I needed "nice" shoes and I was dead wrong. One compromise might be to consider some sandals or flats that are comfortable enough for walking to and from dinner and look good too. My go-to sandals for that these days are Abeos from the Walking Company. I have 3 pair. I also have 3 pair of Abeo flats for weather inhospitable to sandals.
I take one pair of flip flops for around the room, in the shower, at the pool/spa, etc. That means a total of 3 pairs of shoes, only 2 of which, the flats/sandals and the flip flops, are packed in my carry-on.
Over the years, I worked out a clothes formula that works for me. I don't wear skirts at home and I don't wear them on trips. They take up much more room in my carry-on than a pair of pants.
My list is usually similar to the one below. If I make any adjustments, they are to take less because my bag is roughly 20x14x8, including the wheels and I don't go over 20 pounds total weight. I hate layering, but for trips, I have to bite the bullet and do it. This is the total and includes what I will wear on the plane. I usually do laundry once a week, so it's pack for a week and a day, no matter how long the trip is.
1 rain/wind jacket
2 lightweight open cardigans
8 tops (at the moment that includes 4 knit tops and 4 button up shirts -- all long-sleeved)
3 bottoms (currently 1 pair pull on knit pants, 1 pair lightweight jeans, 1 pair chinos)
1 pair hiking/walking boots
1 pair flats
1 pair flip flops
2 pair PJ's that can double as base layers if needed
2 scarves
minimal cheap jewelry
1 small cross body purse
1 fleece hat
1 pair fleece gloves
3 pair compression socks
3 bras
3 shapewear tops
8 pairs panties
1 pair swim shorts
1 rash guard top
Those are the basics for my next trip, 6 weeks, May-June, to the UK. Everything coordinates, of course. This trip's colors are purple and gray. Many people take much less. When I try everything on and try packing it in my compression cubes, things may change. I already did a packing experiment in January on a 2-week trip to Texas and made some changes as a result.
Have fun with the packing planning.