Yes, you can, but not through Fibaro's cloud.
Actually, Fibaro's API (which allows ImperiHome to interact with it) is only available locally on the Fibaro unit itself : that's why ImperiHome can't use the Fibaro 'cloud' to connect remotely.
Then, for remote (outside of local LAN) control to work, you'll have to setup port forwarding by yourself on your internet router/box, and then enter your internet connexion port and ip address (or hostname using a service such as no-ip.org) in the Fibaro config wizard in ImperiHome.
Some general informations on how to setup port forwarding is available from noip.com here : http://www.noip.com/support/knowledgebase/general-port-forwarding-guide/
By default, the HC2 port to forward to is the port 80 (http)
IP Cameras : Please note that, the IP Cameras declared will not be viewable from the app in remote mode, because the current HC2 API does not allow to relay images. If you want your cameras to work remotely, we suggest that you add each camera as a standalone system in the app, with local url and remote url.