Range is actually 390.625 km (read as: infinite, within the scope of the game).
"Burn" gets realll fuzzy real quick, because only acceleration is modeled. But given that the missile goes into space (as in, higher than a satellite) and maintains a constant speed, we can surmise that it's not under thrust despite what the flames coming out the back would suggest.
But man I really don't think "nuclear tipped strategic missile vertically launched from a hardened silo is modeled on an ICBM" is the sticking point in this conversation. Do we need to go house to house on this?