combine the shieldgun&grapple (don't kill me yet, please)
1.0) the grapple becomes the AWO for the shieldgun
1.1) pri fire launches grapple, 2nd fire =hook up
2.0) offhand graple key remains in place, but becomes offhand GrapplerShield weapon key
2.1) this key then either launches the grapple as before, or raises the shield - depending on what AWO was selected for the new gun...
Sounds kinda fruity I know, but it should prevent people grappling to the roof and hiding behind the shield, which I find really annoying for some reason.. Also gives you guys the opportunity to create a new, spikier, more chaotic shieldgun model

Similarly, the offhand shield could be interesting in combination with the Melee weapons...
Okay you can kill me now....