if it is fresh then most likely not, i have had very fresh eggplants (3-4 hrs after getting from field) and it had spots. I am not sure, but i think it is fine, but if it is old, then your hypothesis can not be ruled out easily

eating eggplant for years, it is fine - a general rule of thumb - if if looks good, smells good, doesnt seem wierd to touch, and does not taste bad, it is probably good (does not apply to wild berries/leaves/mushrooms).

I would not.

I did try, but they are not that, lets just say helpful, because I am switching my specialisation, and they say what i currently seeking is more of a fad (it is not, but the are relatively old school folks)

Do not overthink simple things - one spends a lot of time finding answers to things they were already sitting upon. If you are not happy with who you are today - then try to find what is it that makes you unhappy, and try to fix it, that is, if it is something fixable. Somethings can not be fixed, and sometimes are better left as is, or sometimes, you can learn to embrace them.