I have some skepticism for the HIV/AIDS theory, perhaps on the level of say 20-30%.

It takes courage to voice a low but not negligible degree of doubt in a emotionally salient mainstream position. I would expect it to result in almost as much social punishment as in the case of outright denial. (Emotional backlash isn't good at math.)

More concretely, I would roughly say I am only about 70% confident that HIV is the sole cause of AIDS, or 70% confident that the mainstream theory of HIV/AIDS is solid.

I am surprised that those two confidences happen to be the same. Is it not a distinct possibility that HIV is, in fact, the sole cause of AIDS even when the mainstream theory is itself rubbish? (For example, if the theory got important details such as mechanism completely wrong.)