The case/rule that you cite is and is about the definition of legal guarding position.

Can a player draw a PC foul without LGP? Yes, in some circumstances (stationary, not jumping, etc.....all things that require LGP in order to be legal at that time of contact)

The reason the case is a block is that the defender who was guarding the dribbler (implying they were actively playing defense....moving) lost LGP when they stepped OOB and they needed LGP in order to not commit a block. The definitions of block and charge make no reference being inbounds or OOB....but sometimes depend on LGP (but not always).

Right. LGP is defined by being inbounds (among other things).

Much of this, as I see it, depends on the contact created by the dribbler. In a general sense, this would be blocking, as you cannot have LGP if you're out of bounds. It has to be pretty nasty contact created by the dribbler to be a charge, though.

not a charge
 

By rule this can NEVER be a charge. B1 does not have LGP. See 2003-04 Interp.
Therefore the choices are Block, No call, or if deemed so, Intentional/Flagrant Foul on A1.

2003-04 NFHS BASKETBALL RULES INTERPRETATIONS
SITUATION 7: B1 obtains a legal guarding position on A1, who is dribbling the ball near the sideline. There is no contact by A1 while B1 has both feet on the playing court. B1 stays in the path of A1 but in doing so has (a) one foot touching the out-of-bounds boundary line, or (b) one foot in the air over the out-of-bounds boundary line when A1 contacts B1 in the torso. RULING: In (a), a blocking foul shall be called on B1. B1 may not be touching out of bounds. In (b), a player-control foul shall be called on A1; B1 had established and maintained a legal guarding position. (4-23-2,3; 4-35-1)

While you are correct that B1 doesn't have LGP, B1 doesn't need LGP in some situations.

Many people misinterpret this interpretation to mean a defender can never benefit from a PC call while being OOB. This is simply not what this rule nor the case says. The rule it is references only defines LGP and only says that a player can not have LGP while OOB. That's it. Nothing more. If B1's actions require LGP (moving at the time of contact), then it is a block if the defender is OOB (no LGP).

In the interpretation, B1 is moving, staying in the path and, as such, needs LGP. Being OOB, B1 doesn't have LGP. With the combination of being OOB and needing LGP, it is a block. But it is not solely because B1 is OOB, it is also because B1 needs LGP and doesn't have it.

A stationary player, one not moving to maintain a position, doesn't need LGP to draw a charge. The offensive player in such a case has ample time to avoid such a player.