Ok, i'll correct then.

1. Bitcoin code is open source and have been copied several times and duplicates and variations have been made, sometimes by only changing the name, and i have lost count on the number of forks that derived from it.
2. Your circular argument doesn't really make sense. You are just basically describing popularity.
3. Buying bitcoin forks or altcoins doesn't affect bitcoin network security in any way.
4. Yeah, everyone wants bitcoin network to be secure, bit like i already said. Buying "competition" doesn't affect it.
5. I don't grasp what you are trying to say with point c. Network being less secure wouldn't rise the price, in fact it would have an opposite effect. People are buying it because it's secure. Which is one of the reasons there will be plenty of miners to keep it secure. And as long as that stays decentralized enough, it will stay secure.