The durration isn't critical to the role, but creating zones or otherwise altering the battlefield is definitely part of the role. A Martial Controller might 'alter the battlefield' with his mere presence, via threatening reach, intimidation, or masterful tactics, for instance. Or, he might actually take advantage of or alter the terrain - probably with a 'reveal' rather than a conjuration. A caster could make a real or illusory pit apear out of nowhere, for instance, a martial character would have to actually dig a pit or conceal an existing one - but he might do it 'off screen' (that is, without having to declare that he's done so until he uses the power).
6. Powers often force the enemy to do things they'd otherwise rather not do (exit a zone, provoke an OA, attack a particular target, etc). As such they are often keyed to "end of enemy's turn" instead of "start of enemy's turn".
Most powers are keyed to the user's own turn, rather than the enemies, and I hadn't noticed the controller's being very different. The controller has a lot of (save ends) effects that are mechanically keyed to the end of the target's turn, of course.
7. Stats are fragile, low HP/defenses/healing surges
Yes, the controller is generally fragile. The Druid is less so, but /all/ the Primal classes are a little tougher than normal. Controller powers can help the controller defend himself, though. When you can daze/stun, imobilize/slow, create cover/concealment, etc you can keep enemies from atting you as often or as successfully.
Another thing about controllers is that the support for their role is mostly in their powers, not so much in their class features. Combine that with thier relative fragility, and controller powers can be a bit better than those of other roles at the same level. That doesn't mean you have to take that same aproach, though. Existing controllers are almost entirely ranged and almost entirely power-based, but, you could create a martial controller who is primarily melee oriented and who has class features that support his role.