Non-commercial, however that wouldn't make it any less necessary to gain permission before using a copyrighted work.

Fortunately I'm not basing my design on any books or other copyrighted work. Dragons and dragonlike creatures are common throughout the real-world mythology of many cultures, going back thousands of years. And while I've certainly drawn some inspiration from more modern works, ideas are not protected by copyright law.

I know that in the games that allow dragons or draconic descent as player characters, they're usually very hobbled by XP requirements and the like. Are you proposing a game where all players are linked to dragons somehow, then? Because on that scale, it may be worth playing a dragon; your ideas are interesting, and I'm not skilled enough in coding to see any flaws.

Usually because those muds try to balance "powerful" options against weaker options by making them require more work.

Personally I strongly dislike that idea - requiring more effort to have a more powerful character still leaves you with some characters being more powerful than others. Within a competitive environment, players are pretty much forced to take the more time-consuming route in order to remain competitive.

So basically, no, there are no additional requirements. All of the classes represent powerful supernatural beings, and each require just as much effort to build up.

No, although anyone can take the dragon-oriented talents (Dragon Blooded, Red Dragon Descendant, etc).