The effect of "Level Limit - Area B" does not use the chain, it is a continuous effect.
All Level 4 or higher monsters face-up on the field after "Level Limit - Area B" resolves will be in Defense Position. You can change the Battle Position of a Level 4 or higher monster, but it will immediately be changed back to Defense Position because of "Level Limit - Area B"'s effect.
If "Level Limit - Area B" is activated while "Final Attack Orders" is active, then the most recently resolved effect takes precedence and monsters Level 4 or higher will be in Defense Position.
If you Summon “Spell Canceller” while “Level Limit - Area B” is on the field, “Spell Canceller” negates its effect and is not changed to Defense Position.
MESSENGER OF PEACE
The maintenance cost is optional, you may chose not to play 100 Life Points and "Messenger of Peace" will be destroyed.
The ATK of an attacking monster may increase above 1500 after the attack is declared.