I can not seem to find/locate the corpse (near pit at cementary ? according to walkthrough) ?!

Without it, one can not finish this quest, nor - it seems - the next quest. And Barakh does not appear on the scene (near or in the tavern) that "evening"...

I have the same problem, I did the other 2 quests and I can't start this one. I was in the pub at 10 PM and afterwards and no Burakh whatsoever. I have visited all people in town and no one gave me any new quest.

Also: in the same day I see an executor posted outside nokh' boys house. Where do I find some medicine to give them to restore their health ? I tried trading with kids but none had those powders, and I didn't find any cure in shops either.

Please help ...

I found out the solution myself.

You MUST interrogate all 3 executioners first; THEN go to the theatre where you'll be able to ask for mask and overall.
Once you've pasted that conversation, you can finish it anyway you want.

I just ran around the theatre and told this guy he was the one :) Saves you a trip to the cathedral...

Hi Paul,

I went to the one near cathedral and interogated, then went behind the theater and told him he's it. Then I got that suicide cutscene and I have the savegame after this point. I can find no longer any of the other 2 executioners to interogate, nor Burakh in the pub. However I was able to finish successfully the day w/o the overalls quest and w/o the other quest that is asked after the overalls one. However I am still puzzled on how I could get that quest ...

If anyone is still interested there is a corpse right next to the shack with the pile of corpses in it(North of the graveyard on the east side of the shack).But that'll only get you the cloak i cant talk to subarov about the mask cos he is ill and i cant get into the house any suggestions?

Like I said, as soon as you indicate the traitor at the theatre, the scene ends at the cathedral and you no longer have "access" to the other quests. Apparently, finding the traitor triggers the end of the day, sort of speak.
Therefor: you must speak to all 3 of them, then your log will be updated with a comment like "I must be cunning"... This log update triggers the conversation in the theatre. As soon as you see that, return to the theatre and talk to the guy inside. The question "find mask and cloak" will be a choice option now.
What you do thereafter is not that important for the remaining quests; be it that you'll need to finish them before the day ends.