Interesting. Its distinctiveness comes from its square proportions, I think.

The curves of your B are going to need more work, as the weight is pretty weak in places.

The G is giving me a strangely strong "that's from Helvetica" vibe, and I think it might be because a G without a spur would fit the style better.

Yes, the A, M, and O are all perfectly square – the remaining letters are varying degrees of rectangular.

I can see that the B isn't quite right, but I'm not sure how to go about fixing it. Do you think it doesn't have enough weight where the bowls meet?

The G is giving me a strangely strong “that’s from Helvetica” vibe, and I think it might be because a G without a spur would fit the style better.

Good eye. I used Helvetica's G as a visual reference. I didn't take any actual parts from it (stealing is bad), but styled mine after it. I think you're right though; it might jive better without the spur.

Crossbar of E need optically correcting (upwards)

B: That, but more importantly, they don't flow equally into the crossbar. You ought to be able to imagine removing either bowl and seeing that the other is continuous with the horizontal on the outside. (It won't actually be so, but when the glyph is whole it should look that way.) The top almost is, but the bottom definitely is not.

The curves on the uppercase "D" look a little clunky, it feels as though the character has been stretched horizontally. I would bring it in a tad and reconsider the curvature. Good luck with your project.