Material on HVAC Ducts

Hello everyone,

lately we had some concerns over our HVAC system ductwork. This started because the register boot (in the below picture, behind the metal edgework) is wrapped in asbestos and was uncovered durning a bathroom reno. It was taken care of by being encapsulated with a spray adhesive.

Now we were about to have the the vent in this below picture removed however the asbestos contractor stated it was simply fiberglass and to leave it. Upon closer inspection, it does look to be fiberglass. He said it was/is a fresh air intake and hence why it is insulated (we at first could not figure out why a return vent would be wrapped in asbestos in the first place).

Outside of that one register boot, no other runs are asbestos wrapped as far as I know. However, please look at the below pictures - hopefully you can tell me what these questionable substances are. The asbestos contractor believeed the yellow looking stuff just to be harmless paint and wasn’t sure what the white crumbly residue on the register boot was (he said he wasn’t even sure if it was asbestos). He also felt the tape looking stuff was just masking tape. In any case, he didn’t have any worries about these areas however we are still somewhat concerned, perhaps paranoid.

Some of that orangish looking stuff is on the ceiling and gas lines as well.

And on the ducts, none of the material is soft or squishy, it is pure metal. Was there any asbestos done on vents like that that we should be concerned of? Was it just really common to paint vents in the past? (Even some supply/return boots are painted on the insides upstairs).
Bathroom register, asbestos behind black part, encapsulated.
Painted? main trunk line.
More paint on line?

Boot with weird white stuff on it.

Boot with lots of weird white stuff on it and apparently tape of some sort?

Same boot as above.

Same boot again.
Same boot from another view. Masking tape?

Duct that was going to be removed, but is apparently fiberglass.
Another main painted? trunk line.
Painted trunk.

Return duct showing some of the areas coated with the orange paint type stuff.
Supply duct downstairs, painted.
More white crumbly stuff.

Masking tape again? This is the same as the boot with lots of weird stuff above (and it terminates upstairs in the photo of the bathroom register I showed, where there is asbestos wrapped on it within the wall.)
Orange stuff on ducts and adjacent pipes also on ceiling apparently?
Stuff up close.
Display of return run that is coated. Just paint, should I be worried?

White painted? trunk again.

Return with coating.

Fiberglass duct again.

Fiberglass duct again.

Many thanks,