AGRBear & branchg:
You are both right. Rurik was not ethnically Russian, his origins have been identified by DNA analysis as Finnish-Ugrian. He descended from Finnish ancestors who settled in the Swedish province of Uppland. Nevertheless, his family has enough Russian blood in the female line through many Russian marriages to make them sufficiently Russian.
This is not the case with Maria Vladimirovna, who has no recent Russian blood at all going back about 10 generations. Her family is a branch of the Danish royal family which as you rightly point out is German, since Count Christian of Oldenburg & Delmenhorst inherited the Danish crown in 1448?
The point is, back in Russia proper, Maria commands very little support even among Russian monarchists (you are welcome to check the facts out for yourselves). Furthermore in the male dominated world of Russian politics, she has no chance of being accepted even as a republican president. Her main support lies with the exiled Russian nobility, and some more romantic Russian expatriots and diasporan Russians.
In the unlikely, but possible restoration of the Imperial Throne, Russians will not care two hoots about equality laws, they will choose someone who they can firstly identify as Russian, and secondly, someone who can more directly claim descent from Russia's original hereditary rulers. This person would have very limited powers, and will almost certainly be a man.
My personal choice (for what it's worth) would be HH Prince Nicholas Nikolaievitch Gagarin , Ph.D. He has three sons. You can find his photograph and family tree on the Gagarin website
www.gagarin.com. He is a direct descendant in the male line of Grand Prince Vsevolod III, ancestor of Ivan "the Terrible", the first of the Grand Princes to call himself "Czar". The Gagarin Y-DNA is also the closest to the compiled Y-DNA signature of Rurik.
I personally have no issue with a Czarina, Catherine "the Great" was a great leader of Russia, but Russia's political class is unlikely to accept a female head of state. Besides, I think a certain element of ruthlessness is required to fill that post, even with limited powers.