Can a KB vs. KB endgame be declared drawn if a checkmate can occur and the 50-moves-rule doesn't apply in a Blitz game? Bishop and King vs Bishop and King, with opposite-colored bishops, is usually a draw unless a serious blunder happens.
[FEN &quot;8/8/8/3b4/8/7k/8/6BK w - - 0 1&quot;]

What is the requirement for an arbiter in the below position if one party is seriously on time trouble say 2 mins against 15 seconds in a blitz tournament if this party claims a draw?
If the arbiter happens to notice this position, can they call it a draw before the 50 moves rule is reached?
[FEN &quot;8/8/8/1B2k3/3b4/8/3K4/8 w - - 0 1&quot;]
What is the requirement for an arbiter in the below position if one party is seriously on time trouble say 2mins against 15seconds in a blitz tournament If this party claims a draw?
If the arbiter happens to notice this position, can they call it as
draw before the 50 moves rule is reached?

No. Helpmate is still possible hence the arbiter cannot intervene.
This applies with any increment and always in blitz.
The relevant article in the latest FIDE Laws of Chess is:

5.2.2 The game is drawn when a position has arisen in which neither player can checkmate the opponent’s king with any series of legal moves. The game is said to end in a ‘dead position’. This immediately ends the game, provided that the move producing the position was in accordance with Article 3 and Articles 4.2 – 4.7.


The relevant section about quickplay finishes is now -
Guidelines III. Games without increment including Quickplay Finishes
The key parts say this:

III.2.1 The Guidelines below concerning the final period of the game including Quickplay Finishes, shall only be used at an event if their use has been announced beforehand.
III.2.2 These Guidelines shall apply only to standard chess and rapid chess games without increment and not to blitz games.