[Clielldub]

Avoid arguments with your parents at all costs, i think its best to first try to bring them back to salah, leave the other issues to one side for now
Try to find them evidences from barewli scholars who they may accept to tell them that salah is still fardh for them, im pretty sure most barelwis don't believe that salah is maaf on anyone

what i have found with barelwi elders is that at times they do not know how to answer questions as their deeni and fiqhi knowledge is quite minimal, so when they don't know the answers they often resort to strange comments which they probably don't even realize are very damaging to their Eemaan but they feel that they need to justify their belief somehow, therefore don't get into these discussions with them as it forces them to utter things which can take them outside of Islam without them realizing, instead you must use hikmah when talking to them on deeni matters, may Allah make things easy for you and guide us all...ameen