What he needs to do is remove the catwalks altogether, making it into a regular courtyard. No need for railings then, and it gets rid of the unwarranted death pit that is annoying the majority of players.
Edit: take what you want from this... started writing it well before you made your change, then didn't notice that you had until after I already posted... that's what having a kid will do to you
Regarding railings and "death pits"... frankly, some of those railings are godawful ugly, but I don't think that it calls for a radical redesign of the area. Frankly, I'd take those railings off the catwalks and the stairs, and remove the "death" portion of the water area, giving a way to get up out of the water there and making it another route. Defenders will have the height advantage, but people that fall in won't be completely f*cked.
Honestly, the real key to a fun CTF map is balancing accessability vs defendability. If the flag room is too defensible, you get stalemates and nothing moves. If it's too accessable, the flag practically flies out the door, even with a good defense. In the case of the latter, the game moves so fast, it's done before it even started. In the case of the former, the game takes forever, until someone gets bored and makes a mistake. The fun in ctf lies somewhere in the middle, where after a pitched fight one team finally breaks through to win the day.
You're asthetic in the map is great. the fact that the flag areas are "outdoors" is somewhat refreshing, as far as I am concerned. This map has a great deal of potential. The key, I think, is to look at where in the map you want your fights to take place, and how, then use the layout to guide players toward that end.