Probably easier to answer all the questions you have (and will have!) if you can watch someone else fishing the pole properly, or watch a DVD.
Shameless plug 'cause I sell loads of pole fishing films, but I also have some free bits like this:
YouTube- Stafford Silvers
That may answer some questions and will show you can catch loads of fish by fishing with a short pole.
To answer some of your more specific questions:
1. Poles are always broken by anglers, not by fish. So breaking a pole will be down to sloppy fishing or poor technique or both.
2. For carp from 3-12lb at this time of year I would be happy with a solid No8 or 10 or a hollow equivalent. Carp will not really fight at the minute unless you stick the pole in the air and try to rip their heads off. Keep the tip right down next to the water and they will simply follow as you ship back slowly. The only time you will need the strength in the elastic is when you lift the top kit to try to net them.
That will take practise and if you are in any doubt about the amount of pressure you're putting on, drop the top back down and point it at the fish. It will soon calm down again and you will feel the elastic retract and will have another chance to lift and net the fish.
3. You can put your elastic through the top 3, but it would be better to remove the No1 section completely and only elasticate the No2 & 3. You may need to buy a larger bush, but your elastic will work much better for it.
Alternatively, buy a smaller winder bung. There are some on the market that will fit into a No2 section. Ask your local tackle dealer for help if you have to.
Any more questions, don't be afraid to drop me a PM and I'll answer in more detail.