Cool map, but here are two things you should fix:
In the big lava pools, you cut the lava into multiple parts. You should make the faces of these parts that touch each other just nodraw-nonsolid.
And the lighting looks quite boring... as an idea, you could try making your own lava shader so that it emits red light, or put red lights where the lava is.
Would you mind I already run the map on my server after making a proper PK3 out of it? It seems to be already a quite good CTF map with two main capture paths - exactly what we are missing
If you want, I can try these things and send you a edited version of your map with these changes.
1. Open Notepad
2. Paste: ÿþMSMSMS
3. Save
4. Open the file in Notepad again
You can vary the number of "MS", so you can clearly see it's MS which is causing it.