What if my widower remarries later and wants to apply for spouse's benefit on their record? What happens if the amount they receive is higher than the benefits they receive on my record?
In this case, your widower would receive a combination of benefits from you and his new spouse that equals the higher amount.
Can my parent's receive benefits on my record if I've been providing support for them?
Yes, but you must have provided at least half of their support. Also, your parents can't be eligible to receive retirement benefits higher than they receive from you.