well if I were a new player, I would stare upon these rings in wonder, and search the forums for a way to get passed it to get to the alternative path. Also, leaving the modern abilities out allow the player to first experience the first path, and then trying to figure out the alt. paths.
Okay then, think about this analogy.
Let's say SRB2 2.2 comes around. Knuckles isn't in there by default. A new player who at least knows that Knuckles is in fact in the game will be scrambling all over to find out why he isn't there, and then he figures out that he needs to type "addfile knux.plr" everytime he wants to play as Knuckles. Also it activates cheat protection. And the developers reasoning? Oh, right, "you should experience this Sonic path first, we don't want you having the freedom to choose Knuckles path without you going through a couple hoops first".
Plus, how does a new player know it's an alternate path? They could look at it and be like "oh i guess that's where I need to go" and try their hardest to find a way there. But, in actuality they cannot (at least, without adding another file or using (I'm assuming this) Tails)
When I want to play a wad, I don't want to write a new batch file just to play it. I just want to type the single file that I know I need, and then play it. What if, in the future, I load this up, forgetting what it is, and then I remember while playing I need to add Greeneyes to actually get everything. Again, they should just remove Knuckles because he has his own alternative paths and you have to add him.
Also, this is a point I've been subtly hinting towards, but adding another character causes cheat protection to be enabled. Yes, you can counter this by adding the character first, but that's technically an exploit (an unfixable one, BTW).
And, I'd like to bring this up again, you do not have control of choosing stats and balancing your paths on them. You currently have the options of leaving it unbalanced for everyone, send large amounts of time on balancing it for all characters, or just add a new character. I don't know why you are so keen on not going with adding a new character, despite how simple it is to do!