It's a greater bee fly, Bombylius major, a nectar feeder and generalist floral pollinator which pollinates hundreds of species of flowers. It lays eggs near real bee nests and it's larvae feed from the bee larvae.
Your pictures are quite blurry, but I think this is an Osmia, ie a Mason bee (and not a bumble bee). I think you can see a tendency of the “horns” that female Osmia bicornis (red mason bee) have on their heads on your pictures, so this is my guess. Females are much larger and generally darker than males on the thorax and head, and often quite black there ...
This appears to be the underside of a walnut orbweaver:
These orbweaver spiders are not medically significant.
Spiders often lose their legs in wasp attacks. Some spider wasps will remove the legs and then try to bring the spider to its nest for larvae to feed on. Sometimes they drop their spider victims accidentally.
Some will simply deposit eggs into the ...
The animal in the photos is actually a female of Osmia cornuta. The horns are quite visible, which makes us exclude Osmia bicolor, and the thorax is entirely covered with black hair, which makes us exclude Osmia bicornis.
I do not believe that galls are categorically non-mutualistic. However, as noted above, ant domatia (of acacia at least) are not galls, the trees produce them in the absence of ants. However, the size and number of domatia seems to be mildly inducible by the presence of their symbiotic ants.
But back to galls as mutualistic, my argument is that seemingly ...