Rebuild? I liked it till the second one. The third one made me feel worse than the series... I mean, in the second Shinji finally made something which was shounen like (of course, I know Evangelion is not supposed to be a shounen anime, but still) instead of just crying or something. And then, the third movie... Yeah, if I could choose I would like happy ending in which Shinji doens't mess it up, and ends up with Rei :3
About the symbology, as far as I know it was just to make the series seem exotic in Japan (you know, as there aren't really many christians, and to them it seems as exotic as we see chinese or japanese traditions). Dunno if in rebuild it actually means something, but personally I really like the series