Do people on the train speak any english?
That really depends on the class of service and type of train you're riding. Here's a quick introduction to Russian long distance trains:
First of all, all LD trains are sleepers. Unlike Amtrak, Russian Railways figured out long ago that on a multi-day journey a bed to sleep in is not a luxury, it's a necessity. There are three classes of sleepers: SV (1st class, 2-person compartment), kupe (2nd class, 4-person compartment), and platskart (3rd class, dorm-style open configuration). On our trip, we rode both SV (click
here,
here,
here,
here, and
here for examples) and platskart (click
here and
here for examples). In addition, there are three general categories of LD trains: firmenniy ("brand-name", top of the line, makes few stops, most expensive), skoriy ("express" or "limited", basically a no-frills firmenniy, often a good budget option), and passazhirskiy ("passenger", generally doesn't have first class, slow, makes a lot of stops, usually not a good option to cover large distances).
So to answer your question, the chances of people speaking English on your train vary approximately as follows (from most likely to least likely):
1) SV on a firmenniy train - You will typically encounter a lot of foreigners (up to 50% on some trains), often older travelers who booked the train trip through a travel agency in their home country at an exorbitant price. English seems to be the most common language besides Russian. Service attendants are used to the foreigners and usually speak at least some English.
2) SV on a skoriy train - Still a lot of foreigners, but more of the younger, independent traveler variety.
3) Kupe on a firmenniy train - A popular option for foreigners traveling in large groups.
4) Kupe on a skoriy train
5) Kupe on a passzhirskiy train
6) Platskart on a firmenniy train - Foreigners tend to avoid platskart like a plague, but occasionally some adventurous souls will ride it on a firmenniy train to get the "Russian experience." English generally uncommon.
7) Platskart on a skoriy train
8) Platskart on a passzhirskiy train - Foreigners extremely rare. Chances are, not a single passenger or train worker in your car will speak any English.
How was safety- like should I keep a good eye on my stuff?
Generally speaking, train safety has improved tremendously since the chaotic mid-90s, partly due to security improvements. If you ride in a compartment, you can lock it from inside before you go to bed, with a locking device that makes the door impossible to open even with a master key. Few people bother nowadays, though, as reports of gassings/robberies in the middle of the night are virtually unheard of now. Train attendants are much better trained to spot any suspicious activity and quickly report it. We generally left all our stuff (except passports and wallets) in our compartment when we went to the dining car, etc., and haven't had any problems.
That said, there are a couple of "gotchas" that you should be aware of. All tickets are sold per seat, not per compartment. So if you buy one first-class ticket, you'll likely find yourself sharing the compartment with a complete stranger. Note that the compartments are not gender-segregated, either. You can buy out the compartment by buying both seats (or 4 seats in a kupe), but it gets to be an expensive proposition if you're traveling by yourself. If you're traveling with a companion, SV is a great option, but I would avoid the kupe, which you'll have to share with strangers. 90% of the time it's fine, you'll make some friends and have a great time, but you run the risk of sharing your compartment with thieves, drunks, or ultranationalist nutcases on occasion. If you're traveling by yourself and are on a budget, platskart is actually a good option, despite anything you may have heard. It tends to be very safe because 1) there is typically little of value to steal, as the people traveling platskart are ordinary Russians, and 2) people generally watch out for each other wouldn't allow an obvious crime to take place.
