I think there needs to be a place to discuss the history of Snap! (and maybe also Scratch). No "category" seems to be appropriate.
I'm wondering how the Logo forward command became move? One can move in any direction (or sideways) (and if someone is told not to move that would include not turning around). Going forward isn't ambiguous. go forward ... steps would be much better. Even the help image for move isn't very good. I'm not suggesting this should be fixed now but I want to understand how we ended up with a name for a command that interferes with the body syntonic ideas behind turtle graphics. Names are important as the Logo developers understood over 50 years ago.
By the way, I think that go to x: y: is an improvement over Logo's setxy.
I wasn't part of the Scratch design discussions, but I'm willing to hazard a guess. "Forward" and "Back" seem like a natural pair to those of us steeped in Logo, but in real life, if you tell someone to move, they just assume you mean to move forward, because your eyes are in front, and your ankles are built for moving in that direction, and so on. If you want someone to back up, you have to ask for that specifically, but you never explicitly ask someone to move forward. It's not like LEFT and RIGHT, which really are symmetric. If you want someone to move the other way, you're likely to tell them to turn around and then move (implicit forward).
And there's a pedagogic problem with FD, BK, LT, and RT, namely, that collection of commands encourages kids to think that LT means to slide to the left, rather than to pivot.
So I think the Scratch design is reasonable in this area. I'm not convinced that MOVE "interferes with the body syntonic ideas behind turtle graphics," because actual bodies pretty much always move forward. "Simon says take three giant steps." He doesn't say "three giant steps forward."
To me "move" is very generic - "move out of the way", "move over", "move over there", "move to the left", and "move forward" (perhaps the default as you suggest). But I guess the addition of "steps" helps too.
Regarding LT and RT - "turn left" and "turn right" are better when typing isn't involved. The Snap! icons for turning are good too.
Also keep in mind that the block's label is not just "MOVE" but "MOVE _ STEPS", which implies "walking". Therefore in German I've translated "MOVE _ STEPS" with the equivalent of "GO _ STEPS". A cursory glance over the translations gives me the impression that "GO" has been adopted by the majority of translations.
My point about LT etc. is that the Logo names, which you propose as the gold standard for turtle graphics, had their own problems. And having BK in Logo just added to that confusion. When do you actually use BK? I guess when drawing fractal trees, when you have to undo the moves that draw the branches to make your program state-invariant. But you never use BK in the classic turtle graphics things: polygons, spirals, stars. And I guess when you bump into a wall while following a maze. So it could be argued that FD and BK should have been called MOVE and UNMOVE!
But also, the main answer is that turtle graphics isn't mainly what Scratch is about; rather, it's animation -- actors acting on a stage. That's why Scratch runs in Fence mode; we had to make it Window mode so that turtle graphics pictures larger than the stage would work. (And we should really offer Fence, Window, and Wrap, the latter of which is the Logo default iirc. Wrap also works for pictures larger than the stage but has the advantage that the sprite doesn't get lost offscreen.)