A friend of mine just met with Sant Jagjit Singh ji Harkhowalwale. He said it's okay to do paath of these kinds of Banis but don't do lots of repetitions without the appropriate viddhi. There is special viddhi for Brahm Kavach or Chandi di Var if your going to be doing tons of abhyaas of these. It's not for everyone. So speak to proper Mahapurkh before you start doing lots. These Banian are different than our regular nitnem Banis, the maryada for doing lots of abhyaas is much more sukt.
A warning from Mahapursh about trying to do excessive Jaap of certain Dasam Bani