(Yes the first gunpowder formulas were invented by this time, however the earliest printed record we have is dated approx 920AD, guilds would hold these formulas secret for a long period beforhand and there is alot of documented evidence that hasnt yet been dated regaurding the early formation of this substance, mind you the trick is in rifiling, and as such most rockets at this age would be extremely inaccurate up until approximately 1100ad when they learned spinny things miss less,
(But to more specifically address your point, sorry no, not rocketry, fireworks and basic controlled flame projectiles, its basically an explosion at one end you try to orient in the right direction for as long as possible)
as far as the flamethrowers go, they had that earlier than they had even aimable rockets, around 800ad, so I am actually a tad late on announcing this one)
(mind you i plan on being far more rambunctious concerning the combination and exectution of thus existant technologies but for the sake of fun I would like to not reveal my main plan of shenanigans until the first major battle whenever that shall be)