Zikr & Dua

Zikr in a gathering

Q: I have a question regarding Halqah Thikr and loud congregational thikr. Recently I have heard reports from many Ulama that this action is not an ibadah but a bid'ah. They cite the incident of Abdullah ibn Masud (RadhiAllahu Anhu) and the dhikr majlis (which I'm sure Mufti Saheb is familiar with) as proof for their claim. Is this claim true? That the Halqah Thikr is a bid'ah.

Reciting masnoon duas at their prescribed times

Q: Do I have to say duas before everything such as before sleeping, before shower, before eating & after eating, before going out & before entering the house, before journey by bus, plane, train, every kind of transportation, before going to the washroom, before wearing clothes, before intercourse, before wedding etc.? 

Will my Salaah not be accepted if I don't do this? 

Proof of reciting prescribed azkaar by the Mashaayikh

Q: There are some specific prescribed Zikr by the Ulema and Mashaykh which are called "Wazifa". These are certain Azkaar of reading a Dua, or Ayah of Quran or the names of Allah for a specific number of times in order to achieve something. 

My question is that, do we have evidences from the Quran, Sunnah and the practice of the Salaf on practicing these prescribed Azkaar? Can you please list them in detail with references.