In advance, sorry this got a little long.

The language barrier can be pretty tough. For Russia. Do not worry about Helsinki. Everyone speaks English. It is easy peasy moving about. Helsinki is nice, but a bit expensive. Public transit is pretty good if you do not have a car (there is a regional pass if you want to make the trip to Espoo or a surrounding area.) Tallinn is amazing. I love Tallinn. It is old, but refreshing modern. There is a lot to do in the small old city space.

Now Russia is different. Even in St Petersburg and Moscow there will be some difficulties if you do not speak Russian. I was in Gostiny Dvor (a mall or sorts) and there were younger shop keepers that were less capable with the English. Getting the alphabet down is a major help. You can ride the metro much easier and that makes getting around simple (in moscow at least). Not knowing any Russian will mean that you will see the more touristy Russia. The markets and some areas (gyspy cabs) require knowledge of Russian.

A downside of speaking English will be that Russians will overcharge you or at least try to. Gypsy cabs will be pretty bad. Souvenir stalls will be awful. There are a group of stands behind the church on the spilled blood that is ridiculous when it comes to overpriced items (when it comes to these type of stands do not pay in dollars or euros as they give a horrible exchange--50 ruble item costs 3 euros). Museums are more expensive for tourists (non-russians). You will need to pay to take photographs. Do not drink the water. Nothing is ever cold. Street vendors have coolers that do not cool. Bottled water is carbonated ("bez gaz" or "still" for regular water.) Public drinking is common, but illegal (businessmen type people were drinking beers on the bus at 07.00--apparently nothing eases morning commute like a beer). Vodka is incredibly cheap in Russia. Other spirits are very expensive.

Speaking of money, when I was in Russia this summer I found that when it comes to ATMs you should avoid ever getting 10000 rubles as you run the risk of a 10000 ruble note that no once can break for you. 5000 and 1000 ruble notes are bad too. I tried to remedy this buy requesting different amounts to ensure I had something I could spend easily (like 9980 rubles instead of 10000.)

You can take the train to Moscow instead of flying. Megapolis is air conditioned and much cleaner than cheap trains. There is platzkart (3rd class) which is nowhere near as bad as it used to be and I do not think is worth experiencing anymore. Megapolis was enough for me. I hopped onto the metro from the train station and moved about the city. But the train requires Russian to get the ticket at the station and tickets sell out pretty often for weekend trips. Remember if you want to see Lenin in Moscow your hours will be limited and the lines will be long. I did not bother. Oh, and things will closed when you do not expect them to be closed (like mondays and last tuesdays of the month.)

Two cheap things worth doing in St Petersburg if you have the time and interest are boat tours of the city (~500 rubles--~$22US--per person) and seeing a soccer match (cheap seats were ~500 rubles per person in the old stadium).

Russia, Finland, and Estonia have some vegetarian options. They can be found with a little research. A person I know searched for vegetarian internet groups in St Petersburg to get assistance with where to find good vegetarian food. Interestingly in Russia chinese food (китайская кухня--kitaiskya kuhnya)--actually all asian food--is really expensive and not that great.