Answer
(Fatwa: 985/D=196/K=1431)
(1) Doing miswak is sunnah. If one cannot do miswak at least one should rub the teeth with his finger, it shall be equivalent to sunnah and cleanliness will be achieved.
(2) [If it is not unclean] it is not necessary to wash the part again. If one washes, it is better.
(3) No ruling shall be applicable on breaking wudhu on the basis of doubt, the wudhu will be ruled as broken only when one is sure of it.
(4) Clean clothes will not be unclean if worn, but it is better to wash the place before wearing the clothes.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband