First impression: Too much ground space, even when you'll add etc stuff, there's just too much ground to cover both for responding to attacks and for just getting around. You really should think about shrinking most of the areas.
Also, in general, the doorways are too small. Some I guess are fine like that, but most can be hard to navigate into and will just get you trapped and spammed to death, which ain't fun.
Ok, Specific suggestions and comments... with pics!
Last
Needs to be smaller. Needs 2 spawn doors to prevent camping and allow for clutch plays. Needs some sort of cover around the CP, and likely the balconies so the medic has some place to stand rather than out in the open. Also, the vertical distance from bottom to top floor is a bit excessive.
Building outside Last
Seems like wasted potential at the moment, as well as being too large. I suggest some stairs in here to get up the the top floor from the floor height of the 2nd CP area. Also a lower 'flank path' which goes to the right area of 2nd (up to the side area) for scouts to use to push out.
2nd CP area
I'd move the left wall in a bit and get rid of a bunch of the wasted space on that side. Try and sneak the back 'houses' a little closer. I'd add some large object, like a granary crate, to fight around and on by the point. Something to add interest to the area. A balcony where the 'sniper window' is would also be interesting, give soldiers and scouts a place to attack or come from. Also, a stairway to the right path would be good so that it can be used to attack or chase.
Get rid of the train and it's pit. Don't care what you do, but that chasm will ensure the map is never played competitively, which I suspect isn't what you want. No one wants to fall in a pit and get trained on 2nd. You can lose an entire round because of that.
Building going into 2nd
Short and sweet, building is a bit weird how it's laid out atm. I'd move the stairs to the other side and fill up the space a bit
Yard
Overall it's too open... but at the same time can be a hellish trap for the medic. Shrink up the space a bit, and makes the ramps nicer (or stairs or whatever), so the medic can backup without worry. Adding some cover, just a concrete block or a large rock or whatever, would be nice too, something to dodge behind.
I would add some stairs and a higher entrance to mid here too. I'll address midfight things in a second, but having the option is good to keep stalemates at bay. Also, under the stair, next to the right door, add some sort of wall (or part of the stairs) to block some sightlines from left yard to right door.
Mid
I like Mid overall, but I think the option should be there for your team to push up top (don't put health or ammo up there). All the doors here are too small at the moment. I'd also add Crates or rocks or whatever to give some spam cover from the opposing side for your medic.
Remove or raise the ceiling, interior midfights aren't fun because you can't have your Soldiers/Demo do cool jumps if they hit their head on the ceiling.
Mid Side area
Make the walkway bigger, too easy to get knocked off. I'd also extend the 'balcony' bits on either end of the area so that a soldier can position and spam at Scouts (who will likely be the main classes using the area). As a cool idea, I though some kind of tall rock formations coming out of the bottomless pit (I assume it's bottomless) that a Scout can do some double jumps on to get to the top area of Mid would be pretty neat.
ANYWAY... I think the map is pretty good Clan, just need to tighten it up a bit, and I think you'll have a fun map on your hands.