When i compile my my map it takes so long its not funny, and i only have 1 room. i dont get it. why would it be taking so long. and there isnt anything in the room either.

also it keeps saying nexus to small i keep raising the number but it still says it.

3 tips:

1: Dont use CSG substract.
2: Dont use extremely small blocks.
3: Use also models.

Also, don't scale your texture anything below 0.25 when using blocks. Model-only levels provide tons of advantages, I strongly suggest using them instead. 50 times faster rendering speed, otherwise unlimited level area (to four million quants diameter), freedom of size and shape, near-instant build times, and more than just this.

But no static lightning, i think. You have to render static lights onto the model in a 3d-software.
If I am not right, please correct me.

Had the same problem - Have 2 suggestions

The Nexus - Leave the nexus be - If you are using allot of models / sprites Increase the entities allowed in stage with bellow script:

max_entities = 1000; // alows up to 1000 Entities

(Just enter it right before the "Level Load Entry"

Render Times: Obviously make sure all Blocks align but preferably overlap where possible. There might be one block not aligning and A6 is trying to render something that should be rendered. Will help if you can tell us what is taking long to render Surfaces or lightmap.

Nexus shouldn't get much above 192 MB for todays's systems. 64 MB is a decent mid-range and is what I use by default.