Hi Lex, it all looks good to me except that they are all frames containing bee bread & fresh pollen/honey. Those bits in the 3rd photo are as @chau06 said, fresh bits of pollen. I don’t see any hive beetle activity on the frames.
It would be good to get a close up of those grubs you’re finding.
I think a good strategy would be to do a sniff test on each frame before harvesting the honey, on top of that, inspect every frame before harvest just to check on the percentage of caps, as well as make sure there is no brood in the frames, which can happen on the odd occasion, based on personal observations.
The sniff test would be easier once the frames are out. Then if there is rancid honey present, it’s easy to rinse it out with warm water. Let the water drain or dry it out before harvesting the honey.
Good luck with that, cheers
PS, the matchstick test is conducted on brood itself, however only if the cap over the brood is sunken & perforated or on uncapped brood that has turned into a dark brown syrup on the bottom of the cell. You’ll need to google matchstick test for AFB, as well as read up on AFB