Mummypig, the reason posters who have personal experience of alcoholics are sounding negative about the way you are being so lovely and enthusiastic and hopeful, is because we have all been there, done it and have huge emotional scars to remind us.
With an alchoholic, it doesn't matter how much you want them to get better, until they want it themselves nothing will change. And if your father is not asking the questions you have, and is not looking into his treatment options, and is dismissing support groups like AA without having tried them, then he is probably still in a place of denial. The chances are that through your enabling him (not making him take the consequences of his drinking, i.e. researching help for him) he will continue to drink, as he has no reason to stop. Until you learn how not to enable, through Al Anon or a lot of reading, you cannot help him and you will be in a lot of pain emotionally. Seperating yourself emotionally from his disease of alcholism is the opposite of not loving him, it is the best way to help him.
[Almost you need to think of an alcoholic as a small child trying to learn to draw a picture, if you keep doing it for them, you are being kind and really wanting to help, but not allowing them to learn to do it for themselves and they have no personal interest in the picture because they feel they had no part in it and didn't really want it to start with]. [Terrible analogy really sorry].
If you want to try and understand what he is going through, again try Al Anon meetings or you can access the AA big book online and read stories of recovered alcoholics.