Gurfateh
Dear Bro IS Dhillon Ji,
Why das is making you to go in for learning methods or to go to Sants is that Sants have been also doing Ghost Busting which you may not be knowing.
Unlike in Dera you mentioned there in sants attempts are made to salvage the ghost itslef so that it leaves the victom so first a sort of talk is done ie what is the problem of ghost,Belive it that ghost is often in more agony then victom.
As mother of Das had some depressions and people said that it was by some wrong influence but she recovered from medication due to mercy of Akal.Das can feel the the agony of you also.Anyway Das did took his mother to one Ajeet Darbar(Again followers of Baba Ji) as his hindu maternal uncle told them to go there and mother could not be sent alone.
Das did like Path of Gurbani being done there.But his mother was OK by mercy of Akal as the things which they gave to her were lost in way.And Das's mother said that God only will cure her and she was OK.May be blessing of Akal could come via dera as you say.
Why did das asked question about Muslims.Well these guys have no concept of Ghost but yet they treat.
Das read one Sau Sakhi that one sikhin was alsp speaking wrong as if possesed and Tenth Master treated her.
Her husband was told to Read Gurbani.
He was told that such situation has come as she actualy went to a Muslim occultiests.
Das just wants to say that Guru did not use own power but relied upon Bani.
Guru Granth Sahib states Oh Nanak! Why rember who is born and dies.
Only One needs to be rembered who is abosorbed in water and earth(everywhere).
Ugradanti Bani(which is removed from present version of Dasham Granth)
People say Sukh Singh wrote it inn the name of Guru but that has been belived by manay that Guru wrote it.
It states,To the power(Energy in time frame or Rate of ahcnge of energy so it is Shakti while Akal is energy or Amitouj).
Let the worship of those who are born and die destroyed.
We need to rember that we do not have to rember bodies or spirits of Guru or even say book worship of Guru Granth Sahib Ji.
Our God is Akal and we need to live happy in will of Akal.
Das was trying to bring in saints like Baba Isher Singh Ji who did interact with ghost.
or say late Mahant Ji of das's Ashram also had knowledge on it.
What das is trying to prove it that power of Akal works there in dera and Sevdar use the same and name is wrongly givne to Baba Ji or Veer Nahar Singh JI.
Das was not telling you to doubt or enquire from Sevdars there but Das wanted you to leran the Vidya(art/scine) fromm them and you can have your own dera in UK and can help all people there and this could be good for preaching also.
Give a seriuous thought on it and try if sevadars can teach yuo some such thing.Das only wants you to gain some inner knowledge and use it to uplift mankind as you are a couseler also.Das is at your side and himself interested to know more and help das by learning all these things yourself.