Is Doing Dua And Azkar After Farz Salah Bidat?
First two traditions are Sahih. The third is good too. There is no restriction to make a dua or not, after prayer. Objection is only when collective dua is made compulsory after prayer. Dua is something personal talking to God. Collective dus does not fulfil this purpose. However if the people gather for a collective dua, like that for rain, then a collective dua can be initiated.