1 - establish a policy to page customers (maybe they are in security) - hey Delta - the other airlines do this!
This is a standard practice for all airlines, if the lack of it caused you an inconvenience then tell an agent, or preferably a supervisor if available but during a reasonable time (don't stop traffic at the gate during boarding) even if that happens to be at the end of your journey. these types of things are covered in briefings.
2 - hire better people for Customer Service for their phone line and give them counseling if they can't control their snide remarks to innocent passengers
Unfortunatly this is cost saving measure. It may seem like you pay a lot for tickets, but in all honesty the prices haven't changed in 20 years, and inflation certainly has. Until the industry can recover it mostly won't be possible to afford US wages for the numbers of call centers airline call volume requires.
3 - have a policy to assist passengers when a flight is missed regardless o whose fault it is. Other airlines don't offer to put you on the next flight for a hefty fee (as happened to me), they do it for free. Also, how about standby - other airlines do this.
Some airlines may not charge you, but instead place you on the standby list, in most cases get on a later flight isn't a problem given that, but on a busy day you could find yourself stuck in a city all day. What Delta does is confirm you for the next available flight. It not only assures you that you'll get on, but it will probably remind you that next time you fly that you should probably give yourself a little more time.
4 - establish a policy whereby internet and counter prices are the same.
The internet helps Delta to reduce the amount of traffic at the front-line ticketing office (aka the ticket counter) and therefore allows them to expedite the process of checking in traveling customers. The cheaper fairs are there to encourage customers to use that method. The only result of making both the same would be for the online fairs to be the same as the others, and the cost saving to the customers would be gone. Delta is making strides to improve the online experience, including making vouchers issued after March of this year useable online for those cheaper fairs.
5 - don't let the airplane leave the gate 10 minutes before the flight when there are checked in passengers that aren't on board.
At 10 minutes prior to departure the boarding process is supposed to be done. At the time of departure the aircraft should be pushed back from the gate. This is time needed for final paper work to be run and reviewed by the flight crew. That's why the policy states that the passenger needs to be at the gate at least 15 minutes prior to departure.
6 - take is seriously when dissatisfied customers tell you that they won't ever fly your airline again - even with vouchers.
Airlines take matters with customers seriously, but by the same token there is a limit to what can be done. They understand that the customer is upset when they are inconvenienced, but an upset customer often won't be satisfied, regardless of measures taken. Delta hopes customers understand the volitile situation the industry is in as a whole, and can see how Delta is working to improve operations, and quality of service 