Alot depends on how you are approaching the design. It is not clear to me what yopur design apoproach is, but if you are running out of room due to planting things one next to another for some reason, then one way oput is to not plant them next to each other in the IDE and let actionscript do that for you. That way you can design each tile in full view without it it being dependent on its position relative to other tiles.
Yes. it's a tile approach, I'm doing the AS3 and partners of mine are doing the graphics, so they would make up the entire level to speed up my work as I am currently working on others activity in the platform... In this way I can loop through the entire level and look for wall platform and all the others stuff. It's a platform started in 3D and then converted in 2D so the dead line. I would use AS3 approach if I had more time to speed in the platform part of this game, that involves also schoolar activity.