Fairly standard experience going by what has been described.

Slight delay, nothing new here - seems like they made up an hour on the flight to SFO. Giving out drinks and snacks for such a short delay is certainly commendable.

Seat allocations - as previously stated if you really wanted to get better seats then you would have found a way to check in on-line.

Hot planes - whether it's hot or cold you should always be prepared to shed/add a few layers depending on cabin temperature.