I'm a pedophile.
No, you're not.
One problem here is that paedophilia may be variably defined by doctors, or by criminal lawyers, or by the media/general public.
If we use the current medical definition (as defined in DSM-4), the feelings you describe don't qualify as paedophilia. Wiki correctly uses that definition:
As a medical diagnosis, pedophilia, or paedophilia, is defined as a psychiatric disorder in adults or late adolescents (persons age 16 or older) typically characterized by a primary or exclusive sexual interest in prepubescent children (generally age 13 years or younger, though onset of puberty may vary). The prepubescent child must be at least five years younger than the adolescent before the attraction can be diagnosed as pedophilia.
You clearly state several times that you're not attracted to prepubescent children. So no psychiatrist would diagnose you as a paedophile.
This definition is going to be clarified in the next edition of DSM-4, by the way; it's going to incorporate the conditions of hebephilia (primary sexual attraction to early-pubescent children), and ephebophila (primary sexual attraction to late-pubescent children). Possibly you qualify as one of those, but note that such attractions must be primary
Some people are attracted to even younger children, and though I'm not I don't think anyone is in any position to judge them for it. Nobody chooses their sexual orientation, be it heterosexual, homosexual, or pedophile.
People should be judged on their actions, not their orientation; and paedophilic actions are demonstrably harmful and therefore rightly criminal.
I'm a big fan of informed consent.
Good. The problem here is that there is no objective test to measure whether an individual is old enough to consent to a particular action, be it getting married, or having sex, or receiving medical treatment. But societies have to draw these lines somewhere, so they do, and these lines are therefore somewhat arbitrary.
As individuals, it makes sense for us to operate within the law of whatever country we're in.
I also think that possession of child porn should be legalized,
Possibly; but the production of child porn should be illegal. Do you agree?