Okay, watched the video SecretiveOps. The first and only thing I would suggest is simply, spend a little more time developing the areas you have, and perhaps the rest of the first level.
Try looking at games you love to play, examine the detail put into maps. Some engines/games can get away with the odd empty hallway with lights, however as I've found over the years with FPSC, it doesn't look so hot. Especially if there isn't more to the level. There are plenty of members around the community as well, whose work you could look at for inspiration, or just simply some ideas on how to further populate your map.
I might suggest even a quick look down
Wolf's list of WIP's
(That's not to say there aren't plenty of other great mappers in our midst!)
I'd say the opening bedroom is good the way it is, because of course, you don't want to over do it either.
And the box puzzle is less of a puzzle, if the boxes are the
only thing in the hallway, and right in your path. Perhaps hide them a little behind other immovable objects or down another smaller path that branches off. Your possibilities are endless. You could even leave 1 or 2 boxes up on the ledge, forcing the player to realize that they're up there, and pull them down to jump on.
Good luck, if you have any other questions I'd be happy to try and answer. Otherwise, it's just time and inspiration
Life would be much easier if I had the source code.