Very good post indeed.
Please don't take this as criticism but more like slightly deeper study.
In order to gain confidence you need to have courage first as you mentioned.
However to have more courage than self doubt - fear, you need to have healty self esteem first.
Confidence is gained and grows with trial and error. You can learn study in advance but bottom line is you have to go out there and do it.
Self esteem however is more state of mind thing. Advantage of that is you don't need to go out there. But going inside of oneself to bring it out can take more courage actually.
Our society is plagued with low self esteem, especially in boys. It takes more to be a Man. Men are forged. Women don't need such complicated process. Society, media is bend on making boys more like girls. And nothing (besides lack of girls' attraction and frustration) forces us to mature up.
Bigger problem is our up bringing. Parents and teachers prefer submissive, non assertive slaves who do what they are told. In order to form boys in to Nice Guys they inflict on us feelings of shame and guilt. Nursery, divorce can produce these feelings of 'I'm no good' too.
And how many of us were explained that 'Seeking of approval of others' is futile, unhealthy and unrealistic? Not many. Why? Becuse people would like to keep influence on you. And of course they themselves have low self esteem and seek for approval.
This is vicious cycle. From parent to child to child....
How to build self esteem? Your true Self has to dominate the demons/ego/Inner crtitic subself, whatever you call it.
It can be done through meditation (Zen, Power of Now) or by Inner Family Therapy
or just by being extremely honest and aware about yourself and your thought processes/psyche. It is hard to done with all the distractions. Games, Movies, Girls, Porn, Booze, Ganja, Geekery, Shopoholism etc. and your Ego fears introspection and will try to distract you (devil) because it "thinks" it protects you. However the consequences of that protection are sitting home watching TV and bitting your nails or spanking the monkey.
Chasing girls is fine for building confidence but IMH experience that is just another distraction and there is no avoiding the Inner Game.
For best of the best on inner game see Breaking The Cycle