It's All Guesswork
Lord Rock's only contribution to D&D Wiki is the draconic champion prestige class. That makes determining the intent of his prestige class's requirements pretty much impossible.
But I'm willing to speculate. The campaign in which this prestige class would meet with DM approval is highly optimized, probably with PCs using Tier 1 or 2 characters like clerics, druids, psions, and wizards to the best of those characters' abilities... and one player insisted on starting as a fighter. Maybe by level 3 but more likely at level 6 with the nominal fighter PC having advanced as Bbn1/Ftr1/Clr1/Rog1/Mnk2, it was obvious to the DM and everyone else at the table that the fighter wasn't keeping up and wasn't going to keep up. Rather than the DM telling the player, "Dude, just play a higher tier class!" and forcing the PC into retiring or the DM giving the fighter multiple artifacts, the DM said, "I'm going to write up a high-powered prestige class that will let you spend your Wealth by Level on things that let you do cool stuff rather than force you to spend all your cash on survival gear to scrape sadly by."
Also, it's also obvious that the class is based in the DM's campaign. In a section excised from the 3.5 Dungeon Master's Guide the 3.0 Dungeon Master's Guide offers the following advice:
Dungeon Masters should use prestige classes as a tool for world-building as well as a reward for achieving high level. They set characters in the milieu and put them in the context of the world. (27)
But even the 3.5 Dungeon Master's Guide says, "The best prestige classes for your campaign are the ones you make yourself" (176). Reread the introductory flavor text; the DM who wrote that description has a campaign that pits dragon gods' servants against one another, and this is a dragon god's servant. A chosen one. Somebody special. This is a campaign-specific prestige class, and possibly a character-specific prestige class (although it wouldn't surprise me were there a rival with levels in the prestige class on the other side of fence). Perhaps not specific to the same degree as Elothar, Warrior of Bladereach, but it's specific nonetheless.
And that's my guess as to how the draconic champion prestige class came about. The class is a valid solution to that DM's problem, and it's a solution that I endorse: none of the other players would have any interest in such a class, despite its power, because they are already playing tier 1s to the hilt. The fighter player felt left out, so the DM made a class for him that was both powerful and integral to the campaign.
Addressing the Requirements
- Base Attack Bonus +3. This seems low. I think it's probably here at all because that was the PC's Base Attack Bonus at the time. Maybe the intended PC suffered from Level Adjustment, possibly as a half-dragon? Were I DM I would struggle to allow a character taking levels in this prestige class starting at character level 4, entering as a Bbn1/Ftr2.
- Must have regular contact with a dragon. This is a role-playing requirement, so defining regular and contact--and perhaps even dragon--is the DM's call. Is the venerable dragonwrought kobold PC sufficient? Maybe. Were I DM in a similar position to the DM I speculate created the class, I'd have the PC already meet this requirement via the campaign. Depending on the rules used, once a prestige class requirement's met and a level in it's gained, the character needn't meet the requirements any longer, so maintaining contact with a dragon is unnecessary. Any campaign using this class as written would probably have regular contact with dragons anyway, though.
- Pass the trials or rituals of their sect. This is another role-playing requirement. Again, these are DM-driven, but I'd make it something impossible for other PCs to achieve, maybe tests of strength (if the other PCs possess low Str scores) or resisting effects via Fortitude saving throws (the speculative sample PC has a really high base Fort save bonus)--done without magical assistance, of course.
I wouldn't expect any character to enter this class before non-spellcasting characters become obsolete. In a highly optimized game that's usually after level 6, and in a mid-optimized game that's usually after level 9. Your Bbn4/Ftr1 is right on track if the other PCs are all tier 1s; I'd spend the next level exploring the campaign world's dragon gods and seeing what feat I'd need to take as a Bbn4/Ftr2 (or Bbn4/Ftr1/Rgr1 or whatever) to assure passage of the "trials and rituals" when taking the 1st level in draconic champion at character level 7.
But if the other PCs aren't tier 1s or 2s this prestige class will be a much harder sell. And if the other are tier 3 and below PCs and don't already have equally high-powered options available, expect a dragon ambassador and a dragon thief to be pitched to your table shortly after you pitch this.
Addressing the Class
Although I think the class itself could be better written, it's obvious the DM understood it. The DM knew he didn't want the PC's fast healing special ability to work in combat, for instance, and might even know what the description of the fast healing ability means when it says the draconic champion's fast healing "ability continues to heal even when they are past negative 10" although I don't. (I assume it's supposed to bring the draconic champion back to life out of combat--which is kind of cool in that it actually encourages the draconic champion to leap into battle fearlessly without caring about depleting party resources were he to die.) Anyone wanting to include this class in his campaign is going to have to rewrite chunks of it even if he is running a Servants of the Dragon Gods campaign or whatever. Vital information is just missing--the links to the first, second, third, and final molts, for example, go nowhere. A lot of the class is in the DM's head and at the DM's table rather than on the page.
Further, as the discussion of the prestige class shows, DM's'll look at this prestige class and balk. Heck, I looked at this prestige class and balked at some of it. (I don't think an optimized fighter needs the special ability improved power attack at character level 6 to be competitive, for instance.) But I don't think it's designed to be judged, given so little context, by us as general readers or even us as general players of Dungeons and Dragons 3.5 but instead read as a method of keeping engaged a player about whom we know nothing and keeping balanced a campaign that exists only by inference solely on that page.