A full SA2 Mod of SRB2 to be made in future time?

I found a wad that has the hero levels of SA2, used my SA2 Sonic MD2, used a long MD2 for thok, got a wad, tweaked it to have a faster thok and homing attack.
The only problem is:
-No last story
-No dark story
-Characters don't switch in next level.
>Example: Sonic in City Escape, next level he doesn't change into knuckles. Multiplayer skin changing fixes this.
I might get a Shadow, Rouge, Eggman, Knuckles and Tails SA2B models, use SRB2CB and use wads, make dark and last story, AND (Somehow I will...) make the characters switch in the levels. I don't know how to switch the characters, though. Is there any possible way to do this?

And... you are aware you would never be able to release it without the original author's permission, right? Forceskin can be used to swap characters, but to be honest, I wouldn't pursue this any further without first contacting the author.

Well that's a good thing, I've been wanting to play the Last and Dark Story levels, but remember, all things ported from other games either turn out poor or unplayable.

But I'm interested in this, how exactly will the Last and Dark Story levels play out with SRB2's Physics?

Oh well, good luck trying to make the full mod.