One can never avoid challenges entirely, but there are some things that strike me as possible amendments if one is working the bill as is, although there have obviously been other critiques of it that could call for other reshaping.
Thinking of it from as is, I would restrict clause 7 so that the bill is purporting to bind only the federal Crown and isn't trying to say something about the provincial Crowns, because that's not a matter for the federal government to decide. That would be an amendment to clause 7.
Clauses 10 through 17 should be amended in some way to operate subject to agreement with individual provinces, which I hope they would offer, but otherwise, to the extent that they're applying off reserve, they're running into provincial jurisdiction. Therefore, an amendment could be crafted to require provincial agreement to the off-reserve application.
Maybe there could be something of the same sort in respect of subclause 22(3), because again, once it's applying off reserve, there are some difficulties there.
I'll stop.