2 questions

Q1:
Player 1 has one of:
Propaganda
Ghostly Prison
War Tax
Sphere of Safety
Norn's Annex

+ active one of

Whipcorder
Leonin Bola
Puppet Strings
Icy Manipulator
Master Decoy
...

vs player2 with both, flying 15/15 annihilator 6 Emrakul and flying 20/20 Marit Lage token wanting to attack for the win, but having only mana resources to pay for 1 attacker. He pays for one. Is there a room to tap the attacker and avoid attack altogether, or player2 can re-choose and attack with one attacker, ie. the another, anyway?

Q2:
Player A is the Monarch and has Solitary Confinement in play. He is attacked, combat damage is dealt, but prevented. Does he remain to be the Monarch?