here LadyGriz. Just let me say that I love your big Western Cedar!
That is a showstopper for sure.
Are those 5 gallon buckets under the leak of the shed to catch rain water? If so, good for you!
Nothing in nature is in a straight line, therefore that is what your eye is seeing and that is where the problem lies. I would remove the gravel line next to the pavers and soften along the path edges with some Buddleia bushes. They grow fast and will give great color and food for the butterflies. I would put some cottage garden perennials along where you have the new plantings and remove the river rock and keep that same half moon design but bring out the whole thing to look like a crescent moon.
The Cedar chip path needs something to give it definition, but not too much. Mondo grass, Liriope, Snake grass or ferns are some good choices and would soften the path and make it look cohesive.
Your dog has chosen that tree to lie under and I know all about that. We had a wolf dog years ago and he chose a place on the north side of our house and dug it out to lie under. It was good and shady and no matter what I did he continually went back to that place. In other words, it's probably not going to change and I would make it as comfortable and sweet for him as possible. A pack of Camomile seeds or sweet alyssum would do the trick. You can get seeds at The Dollar Tree for 25 cents.
May I also suggest Better Homes & Gardens website bhg.com. They have a garden planner that lets you do a garden layout with all kinds of design elements so you can just click and drag and see what the whole thing will look like and it's free. I believe you can also see what it will look like years from now. It's great fun and will help you get a feel for what you want to do.
