It’s normal to see some leniency for the 50 lb weight limit, but not the 70 lb limit IME.

Presenting bags for checkin after the checkin cutoff time requires “voluntary separation,” which means you voluntarily separate from your bags and accept the risk that they might miss the departing flight since the airline didn’t have enough time to process the bag. The alternative to refusing to voluntarily separate from your bags is getting rebooked for a later flight.

Reporting mishandled bags within 24 hours of arrival for domestic trips is vital; otherwise, the airline’s off the hook for compensation.

For assessing damage to contents, the rule of thumb is if the exterior isn’t damaged, then the damaged contents were just packed inadequately. If the exterior was damaged, then damage to contents can be covered.