Administrative units of the first and second levels are widely accepted and used in Russia.
Level 1 administrative units are generally correct except Moscow City / Moscow Oblast border which was subject to change in 2011. Nonetheless, all provinces borders are too generalized. Therefore, we uploaded more precise polygons as places in some cases. For general Russian public, it might be wise to introduce Russian names of administrative units due to presence of the Russian interface and vernacular names for species. Magadan Oblast has false name and therefore could not be find through the search.
Level 2 administrative units, or rayons, are also generally correct (once again, in Moscow City and Moscow Oblast they were slighly changed). Introduction of the Russian names of rayons could also be a great improvement.
As for translation, there are some bugs and/or minor errors in the Russian terms. Few months ago, Moscow University staff member @antennaria send @katya a list of some improvements, but as far as I know they were all rejected. The main problem with the Russian language is the presence of a complicated system of grammar cases with a variable endings of the words. So, species might be вид, вида, виду, видом, виде, виды, видами, видах, видов, depending on context.
There are some problems with the Russian vernacular names. The first letter of the epithet is capitalized on iNat, but this practice is really never used in Russia, except for species named after people. I would say, that this could be regarded as a grammar error. For instance, Chelidonium majus is “Чистотел большой” in Russian, not “Чистотел Большой” as indexed in iNat. Some names are very old-fachioned (like “Кашка” for some Trifolium species, instead of “Клевер”).
For the Russian vernacular names of vascular plants which are still missing, we could help using Moscow Digital Herbarium database. Just send me a list of accepted vascular plant species, genera and families with missing Russian names as xls or csv, and we will try to fill it in automatically. It might be wise to add a current number of observations to start a manual inserting of names from the most popular species.
To improve iNat outreach in Russia I would suggest to start a regional extension like NaturaLista, but I do not see anyone who can do this task in near future. So, may be one trick - to change a logo from “iNaturalist” to “яНатуралист” in the Russian-language version. Why not?