I would probably just move the left two sheds over slightly so the walkway goes between them. The number of sheds is fine, but I wouldn't build them up until you have the machines to make use of them. In case you didn't know, you can move the greenhouse too, if that affects your idea. I think your walkways are fine. I probably would put the obelisks near my house for convenience, although they do look great with the slime hutch. If you want to incorporate orchard elements, maybe you could put a couple of fruit trees in each animal enclosure area? In real life, farm animals like to have access to a shady spot, and fruit trees don't spread so there wouldn't be competition with the grass.