IOTL, just when Tsar Paul switched sides in the Napoleonic War and was planning a exhibition to India with France, he was assassinated. WI he avoids assassination and Russia joins France? The man does not strike me as a pragmatist, show a drop of Russian exports does not seem to me grounds that he would then switch sides again. However, would Napoleon make sufficient concessions to Paul? Would conservative monarchies be propped up in Prussia and Austria? Would they succeed in Iran and then India? Even presuming it all falls apart and the Czar lives to 1824, what happens to Russia and France in this event?
Well, of course the "Indian expedition" was more than a little bit on a fantastic side but it was conducted by a small number of the Cossack troops and would end up as just one of the many unsuccessful Russian expeditions into the Central Asia that happened before and after Paul (in that regard he was not more "eccentric" than Peter I or Alexander I).
Of course, he was not a pragmatist but (a) his foreign policy was not too much more aggressive than one of his mother (who started Russian involvement on the Med) and (b) he switched sides only after being fundamentally screwed by his allies, Austria and Britain and the British violation of Denmark's neutrality. Nappy did not have to make any noticeable concessions to Paul because his participation in the 2nd Coalition was a purely "cabinet" action.
The Russian exports were, of course, dropping but this worked in both directions (hence British-sponsored assassination). However, as was demonstrated few years later, between Tilsit and 1812 there was a distinctive growth of the Russian domestic manufacturing (usually suppressed by the British imports) combined with the lower bread prices. Probably sooner or later the Brits would give up their policy of searching neutral merchant vessels (anyway, not too many Russian merchant vessels existed at that time so Paul, again, was acting out of principle defending interests of the Baltic countries with the merchant navies).
If Paul survives the assassination plot (and does something nasty to Alexander and Constantine after their involvement is discovered) then he has quite a few years in his disposal until Nicholas grows up. Which means that there is most probably no 3rd Coalition because it is quite questionable if Francis II would risk to face Napoleon on his own. Probably the same goes for the 4th Coalition: would Prussia risk a war without Russian assurances? However, if in both cases the war happens, then both Austria and Prussia are beaten with a lesser effort than in OTL (most of the post-Jena Prussian fighting was possible only due to the Russian involvement).
Russia would probably keep acquiring the territories in Caucasus region (as it did under Paul and his successors) and perhaps starts meaningful expansion into the Central Asia. If the Ottomans are not incited by Nappy (as in OTL against Alexander), then the Russian empire is mostly at peace.
Which leaves an open question of Napoleon vs. Britain: if there is no "Russian resource" (aka, ruler idiotic enough to keep fighting for the British interests), perhaps Britain would sooner or later have to reassess its position and agree to some arrangement.