Hearing someone's conversation

Q: My question is, what happens when you hear someone's conversation while having bad thoughts but then you realise during the conversation that you were not supposed to hear it and immediately divert your attention? Do you get the sin even though you diverted your attention right away or do not get it due to you not remembering that specific commandment of Allah Ta'ala?

Sufficing on the faraaidh of ghusl

Q: If a person fulfils all the fardh of ghusl that is gargling the mouth three times, making water reach the soft bone of nose three times and washing the body thoroughly such that no part remains dry, is the ghusl valid or the sunnats of ghusl have to be performed too? Does skipping the sunnats render ghusl invalid. Also one of my cousins told me that ghusl means wetting the entire body. If this is so then why does ghusl have faraaidh?

Waswasas and doubts

Q: I have been suffering from waswasas and I try to ignore them. But everyday I perform ghusl as I am not certain if I became junub. What adds to my doubt is I can't put on underwear as I suffer from allergy. Now after Fajr Salah or Zuhr salah I take some nap, then I fear whether I need ghusl or not. In such scenes, I check my private part, when it's dry I don't take ghusl and when it's not, I take ghusl. Am I doing the right thing? Also being a female, discharges occur frequently so it's hard to distinguish.