The phrase "en todo cuanto" can shift meanings depending on context ("infofar as," "including," "as regards," etc.). In the first sentence (whose subject appears to be missing its verb?), I think simply translating as "in everything" would work best. This is how I would render the whole sentence (though again, it's a bit difficult since it appears to be incomplete):

Here, the modern museum—and its analogues, through their spatial and symbolic distances—in everything it includes and in everything it purports to exclude, in its persistent yet unfulfilled promise of autonomy...

And the second sentence, which also appears to be incomplete (missing the verb phrase) and includes what seems like a typo ("de y para"), I would translate something like:

Furthermore, the white cube— that "commercial, aesthetic and technological discovery," as Brian O'Doherty describes it—to the extent it can have, through its specific privilege and refined destiny, through its architecture and in the aesthetic experience [it inspires]...