Contradiction between the legal form and practical substance of politics as practiced by the ruling elite in Russia is indeed one of the main reasons for the permanent state of crisis that Russia lives through. It is tempting to look at it as one of the many facets of transition from an empire to a nation state (as Geoffrey Hosking thinks).
I would slightly disagree with you saying that the 1993 basic law remains a kind of sacred cow. Although it wasn’t changed in many basic aspects, at least two (and in fact more) changes definitely transformed the spirit, if not the letter of the Constitution. One is lengthening the presidential term to six years, and another appointment, rather than election of regional governors. The former enshrined the supremacy of the super-presidential executive, the latter had a very serious impact on the substance and understanding of federalism. Finally will the conflict between the unitary and federal impulses come to a head during the next 10 years, in your view?
Konstantin von Eggert