Transit at VVO?

I realise there is little information on transit at VVO.

Is a transit visa needed at VVO?

My idea is to fly into VVO with S7, and depart in another alliance carrier, so I am not sure about the through luggage check-in, especially when I fly out with a ex-VVO ticket (2 different tickets). I am also considering just carry-ons if it simplifies the process.

How is VVO airport like for a transit, and if I need to clear immigrations and re-check-in, would there be difficulties/long process?
Or is there a good transit area for different airlines for me to sort it out without going through immigration?

Many thanks!