There is no problem for u in all of above written questions,, the bedsheets and and the rooms became najis when it wash by Hindus,, but if u r dry then there is no problem, u can do your prayer in dry situation on that bedsheets, only your sajdagah must be paak,, when u r using the semi automatic washing machine first u should wash it then u can wash your clothes,,,, najis clothes never became paak by sun,, only non removeble things such a wall became paak by sun