Well, in essence you have a few question in that one question. Meaning there are many subjects covered in that one question of yours.
I will simply state that that is old code. Meaning in real life you would not use the <bean> and the FactoryBean directly in your xml tags to setup AOP. Instead, you will use the aop namespace, like <aop:before>
I recommend finding books or tutorials out there that are more up to date.
Like "Pro Spring 2.5" from Apress, or wait a month or two for the better books on Spring 3.0