Speaking of riding rockets, I've not tried the Alt-Fire of Rocketjump before. How does that work out and when is it actually useful?
From the DoomRL Wiki, with some extra information added for clarification:
Rocket jump. The rocket explodes just one square away from you, propelling you around. This is not the same as an ordinary rocket explosion; it does 1d7 impact damage if it hits a monster (in addition to splash), does half damage to you, and does 3.5 times more knockback to you (knockback = damage / 2). Expected knockback from a 6d6 rocket jump is thus 10 squares, 8 with Badass, 0 with Fireangel. For technical reasons, this will not work at all if a wall square is used as the center of the blast.
In simple words, the amount of damage you take is equal to the amount of spaces you are knocked back. Hence, if you need to get somewhere that would cause you to take more than, say, 10 damage (such as across the lava barrier in the Halls of Carnage) you're statistically better off rocket-jumping across. I could also see it used to "jump" across gaps where you know Revs/Viles are otherwise going to fire at you, Hellish Caves with rather large lava rivers, Arenas just to get away from the middle...possibilities are pretty various.
Though, to be honest, I can't say I've used it for more than testing that it worked at all. It's a situational tool that gives you even more reason to opt for the Juggler trait.