Is it permissible for me to pray behind a Sunni Imam for Friday and for regular congregational prayers, and…

Answer

Taking part in Friday and congregational prayers of the Ahl-e Sunnat is permissible in areas where Taqiyah (dissimulation) is required. If you are not going to face a problem, you should, as far as possible, prostrate on something upon which Sajda (prostration) is permissible. Prostration on carpets in the case of Taqiyah or out of necessity is permissible and there would be no objection in it. Also, it is obligatory upon you to recite first chapter al-Hamd and the second chapter yourself – with the recitation in a low voice though. In any case, Friday prayers performed with them is not sufficient for Dhuhr prayers. Therefore, it is necessary to perform Dhuhr prayers separately.