The sleeping bags could be used for vampires if they are the "mummy style" bags that zip all the way up - two styles of sleeping bags would be preferable to just one type.
I miss Clair the Bear (from Sims 1/complete collection) getting into the bee box and having to flee as a swarm chases her. I would like to see something like that in Sims 4 outdoor retreat with the NPC bears. Also, add the wild foxes from Cottage Living to outdoor retreat. (And for heavens sake, fix the wild fox thumbnails!) More styles of ladder would be great, too. I have often found myself dissatisfied with the limited styles of ladders: they ALL look like dock ladders.
Plus, add a new lot type: Treehouse. The treehouse should have some kind of "tree trunk foundation" that actually looks like a tree trunk with thick roots (or round walls with tree bark wallpaper), and a roof that looks like the top of a tree. Multi-types for lots would be perfect here: Residential rental lot or timeshare: a vacation home that can also be used as a rental for selected days (would require the Seasons calendar). Treehouse requirements: Stairs or ladder, living or dining chair, a grill, a picnic table, 5 plants, and a toilet (such as the toilet bushes or public toilets), and an end table. Or, stairs, treetrunk foundation, treetop roof, and tiny house requirements.
Regardless of whether they add the treehouse lot type, at least the tree bark wallpaper and rounded walls should be added, along with support or a cheat for building floors regardless of whether there is a first story/ground floor beneath them.