I just gave it a quick listen on my earbuds through my phone, but here's my take on it so far. The low end seems to be a bit muddy, without any distinction between the guitars lower frequencies and the bass guitar. I would firstly try to clear that up with some eq and perhaps some multiband compression.
Secondly, the kick and snare is nice and loud, but i struggle to hear the hi-hats and the rest of the cymbals. Make some space with eq and bring 'em up a bit to cut through.
Other than that i don't have too much to add, and will definitely like to listen again when i'm at my monitors.
I think it's all English, but he meant that they all speak Russian natively
The guitar and bass sound good together to me. Very crunch and heavy.
I'm not a fan of that kick drum. It's very clicky, even for metal.
Vocals sound fine. Your pronunciation isn't bad
That guitar solo is not great. There's some crackling on it. It sounds like something in the recording chain distorted that wasn't supposed to.