#2
I saw this behavior of Vespa crabro, on layings or even of the adults of Homoptera Tingidae on pear tree under bark, it sucks the sweetened matters (miellat). ? It disputes with the ants besides for the meal.
#3
They truly just eat about anything don't they.
I've seen them flying into spider webs and knocking the prey out of it. After that, they just eat it, leaving the spider hungry.