Yarrow leaves are more finely cut, IMPE, unless there are other cultivars I am unfamiliar with. I've seen a lot of the yarrow that grows like weeds in CA at my sister's house.

Yes it’s edible. All brassicas are. Whether it’s palatable and how it’s eaten are up to you to decide.

The first is not clear enough to tell...could be several possibilities. The second looks like Rhipsalis, mistletoe cactus.

My blueberries in the ground get to fend for themselves and do pretty well. We pull the weeds (mostly) and mulch the beds (leaf, bark bark, pine needle, whatever's handy); if its super hot and dry they might get a round of watering, and if I have some extra water when running around watering new plants, I'll dump the end of the watering can on them. Mostly they get treated like the rest of the perennial garden, which gets no special care unless plants are risking getting crispy. They have adored our rainy July this year and have been giving bigger berries than previous years. We have mildly acidic soil, near neutral. I'd go take a picture, but, go figure, it's raining. These are my favorite resources for northern highbush blueberries: https://extension.umaine.edu/publications/2253e/ https://cpb-us-e1.wpmucdn.com/blogs.cornell.edu/dist/f/575/files/2015/12/7blueberries-2mndel3.pdf