Yes, it is....
Yes, I used it in my pool to plug the conduit entrance from my pool light.
it said made in Mexico
I wouldnt use thias product for that application. I thiubnk it would work best between 3 smooth. c;ean surfaces (not brick in this case). I'd use a polyurethane sealant like Sikaflex.
There's not enough information to answer your question. Auto use in general like body leaks, 'yes' great stuff. If you are talking about moisture getting inside a lens, the answer would be 'no'. You need to replace the headlight assembly. You may be able to buy a used assembly at a salvage yard.
It might work if the gaps were small. It doesn't flow like an tube-based caulking.
butyl tape makes a waterproof seal by being compressed between two surfaces. Likely much better than silicone for the headlamp application where an adhesive would work loose due to movement.
You really need to contact the manufacturer for those details.
no it will oozed out of place
I wouldn’t. Butyl tape is sticky all the way around, not just on one side. It will just collect dirt and end up looking terrible. I would recommend a masonry crack filler.