1)
Why did he say "I do not desire Mohar (money to be Mekadesh my daughter)"?
1.
Radak (23): David had said 'I am poor', i.e. I cannot give a proper amount to be Mekadesh the king's daughter.
2)
Why did he request Orlos of Pelishtim?
1.
Malbim: When nations fight and kill normally in war, there is no hatred for the general. If one comes upon people sitting serenely and cuts off their Orlah in the way of disgrace, this is not the way of war, rather, a tormentor. Surely Pelishtim will hate him and find a way to avenge him!
