Answered by Ustadh Tabraze Azam
(1) Is saying Amin when reciting Qur’an outside Surah Al-Fatiha permissible?
(2) How do you know if you are doing things for Allah and not to show off? Sometimes I find myself not doing a good deed when there are people around me because I am scared that I’m not doing it for Allah.
(3) How can we have a clean heart? How do you know when you have a corrupt heart?
I pray that you are in the best of health and faith, insha’Allah.
(1) Yes, it is from the sunna to supplicate for the virtues and blessings mentioned in the Qur’an.
(2) Not doing things for the sake of people, too, can be considered a form of showing off. In general, voluntary acts should be done in private and obligatory acts in public. However, ask Allah for a high intention, facilitation and acceptance.
(3) I’d advise taking the classes on Spirituality at SeekersHub. Please see: Spirituality Deparment
And Allah alone gives success.
Checked and Approved by Shaykh Faraz Rabbani