Hi,
i gave your map a quick look. Here are some recommendations I have.
Starting with the textures (i know that you will fix them and you also know this "rule" -- but i also know that new mappers tend to look at the most recent posts before actually starting mapping, so i felt like i had to write it). Try to allign textures right at the start and not at the end of mapping. Thoughts like "Ew, i will correct it when I'm finished" will never work. It will be just too annoying to look at every brush twice at the end (same with the content and surface).
Also, consider changing the marked textures at the picture ice_texture picture(I really hope i can attach them).
I feel like stone would be more fitting than the actual texture. And for the perfectionism, you can see clear texture lines on the walls (referring to the stone_texture).
No idea how to create the smoothness in bsp, last time i worked with that editor was months ago. But I'm pretty sure that its only like 2-clicks to do it in TB (select faces with the stone texture -> reset texture alignment). 3lf can correct me if I'm wrong.
The Ice-To-Flag jump also felt kinda ugly. I'm not the best player, nor am I a good jumper but even when i started at the start of the ice (which is the ideal case) i had somehow difficulties to reach the flag and/or keep my momentum after grabbing (because i had to turn right to my base). I know that you probably know what you are doing gameplay and jump-wise in your maps, but i think that part could be somehow improved, even if it is only a minor annoyance.
The spawns for red are facing the walls. Is that a wobluda/dhemap thing or unwanted? Either way, it can be really annoying (especially for such a "small" map). I also think that the skill-level of a player must be high to actually use this "advantage" against other teams or players.
R_speeds are really good, 1000-1500 is absolutely acceptable, however optimization never hurts. The room is still rendered although you cant see it directly. Test it with gl_showtris 1. Personally i think a fancy door entity shouldn't be used for such a room, consider using mist and maybe even an areaportal to lower wpoly. (More infos for areaportals:
https://forums.digitalpaint.org/index.php?topic=8394.msg87974#msg87974)
3lf already pointed it out, the lighting is a huge turnout, please make it more natural.
My last recommendation is another minor annoyance. The walls on the maps are really flat and could be made more detailed. Best examples are probably all sanctum maps and cream. It would definitely give your map a special touch!