Do you think grape vines will fit with the plant that is there? It's a vine as well. I'm hoping it takes over the fence in the next year or two. I'm not sure how quickly they grow though.I'd do at least two more bushes. Look for "lavatera" and "blue hibiscus". Both of those do really well in harsh climates. A couple of grape vines along that fence would be great too. In between the pen and the wooden fence. Then I would add a second water source.
Your dandelions probably won't grow until next spring.
In my experience the more time they spend outside at this age, the more they will pyramid. I like daily outside time for sun grazing and exercise, but I keep it to a minimum until they gain some size. Mine don't stay outside all day until they are 5-6", and even then, they still sleep inside in their humid closed chambers.