Can you use a heavy shield in two hands when you attack with it useing Improved Shield Bash and still get it's shield bonus to AC?
This would add damage to a shield build.
also when two weapon fighting with a Heavy Shield and a Short Sword, can the Shield be declared the primary weapon?? or dose it have to be the offhand weapon?? [/QUOTE
I don't see why you wouldn't be able to use both hands on a heavy shield for the 1.5x STR damage. You are basically putting your entire body behind the blow. And Imp. shield bash is pretty clear on keeping your AC while bashing, so that shouldn't be a problem.
Unfortunately, shields are expressly called out as off-hand weapons.
Shield Bash Attacks: You can bash an opponent with a heavy shield, using it as an off-hand weapon.So RAW I think you are stuck with that. Not that I think there would be any problem swapping things around. Shield bash is not exactly game breaking, mechanically...
Can you use a heavy shield in two hands when you attack with it useing Improved Shield Bash and still get it's shield bonus to AC?
This would add damage to a shield build.
also when two weapon fighting with a Heavy Shield and a Short Sword, can the Shield be declared the primary weapon?? or dose it have to be the offhand weapon??
Yes, yes and no.
Under its listings as a weapon it meanly says that if you attack with it, it is considered a bash.
Shield, Heavy or Light: You can bash with a shield instead of using it for defense.
The rules say it can be used as an off-hand weapon but doesn't mean it can't be used as a normal weapon. The description listed above is missing a key word of "only" in there eliminating its use as a normal weapon.
People have been arguing this fact a LOT, but in the end there is no limiting rules to state you can't use it as a normal weapon.