Alright. I downloaded this map and ran through it.
It's pretty good for an a1. You did state that you were still testing it, so I'll keep it light.
(Additionally, will images automatically resize if I put them in the IMG tags? Because when I preview it they come out huge and un-resized)
There are quite a few sightlines around here, not necessarily a bad thing but still something to think about.
Lighting's weird, but since it's a1 it's not a big deal.
This area's pretty flat, and has very little flanking routes. Add one to the left as a cave or something.
What's the purpose of this room? I couldn't figure out what it was for.
You did say that there was a height advantage. I think this is a little too much though. Snipers will dominate due to the height and ability to retreat easily.
Additionally...
...the first point seems verrry easy to defend due to the huge height advantage for soldiers and demomen to rain spam down upon the first point.
Widen it a lot, add more flanks and probably either lower the height advantage or cut off access to the roof entirely. Otherwise it's pretty good.
This hallway seems overly small. Widen it because it appears to be a main flanking route.
Just a nitpick but this seems like awkward placement of health/ammo.
This room seems pretty useless for the effort it takes to get up. Extend a ledge from the side the windows are on to make it more open or otherwise open it up to the tracks.
from above, a.k.a. extend a ledge out from those windows or something.
Personally I think this room has a lot of prop spam. It IS an alpha 1, so that doesn't matter much.
The one gripe I have is this:
The payload track is not the main focus of the room, and it should be. It seems extremely easy for the blue team to push the cart along the edge, and once they get in the tunnel above the room...
It will be impossible to defend.
I remember reading somewhere that the payload track should be the primary focus of a map. Put it through the center of the map or something, *it's still an alpha* so you can experiment a little.
Again, this is the only entrance to the final point, so defense-wise it would be tricky.
I figure the reason the cart goes through here is because you still have another point to design (as referenced by the extra point on the HUD)
Altogether, pretty good for an a1, I'd focus more on gameplay than anything else. I look forward to what this becomes, if I made any mistakes just tell me.
Cheers.