If you're trying to make it looks like the N64 version, I would recommend purposely misaligning your textures and adding holes showing the skybox too give the map that awesome unfinished-looking-but-still-an-awesome-map feeling. That's partly why the Citadel (Hacked version) remains my favorite multi map in GE64. What's great about this is that many of the textures are already made into the mod, they just need to be applied, rotated, and scaled to match that of the original Citadel's textures. As for the weapon layout, I would recommend taking a look at Zoinkey's Citadel (The version made to be played on the N64 via a patch with the Goldeneye Setup Editor), as the weapon layout there is very well balanced (even if Beta 1.x's guns aren't).
Oh, and to make the ramps look completely 2D(As they appeared on the N64), you may want to try taking the already thin ramps you have, and nodraw the sides.