What is the ruling on obsessive doubt concerning ghusl (ritual bathing), and doubt regarding the completeness of purification after ghusl or wudu (ablution), and the feeling of exhaustion due to excessive cleaning because of slight oily layers on some body parts? And what about someone who suspects nocturnal emission daily? Is she blameworthy if she falls short in responding to these obsessive doubts while doing what is within her capacity?

If you immersed your body in water with the intention of performing the obligatory ghusl, then you have completed your ghusl. Rubbing the body (dalk) is not a condition according to many jurists, and this is the fatwa given. You have done well by not repeating the ghusl unless you are certain it was not completed, and by not performing ghusl unless you are certain of its obligation. Do not pay attention to the waswas (whispers/obsessive thoughts) related to seminal emission (ihtilam) or the presence of something on the body after ghusl. The default state of the body is purity. Whoever doubts ihtilam, the default is that they are pure. And whoever finds something and doubts whether it occurred before ghusl or after it, it is attributed to the nearest time, which is after ghusl.