well i know that high corporation tax wouldn't help them, and a lower tax mean less incentive to shovel anything into off-shore tax havens. the problems you highlight are not dependent on corporation tax either way.
the point i'm making is that its standard economic theory that corporation taxes lower investment (why invest here at high tax, when there is low tax?) and the case is usually made for it having a negative impact on employment and salaries (lowers RoI, so other areas of cost are reduced to compensate). we like to tax companies because they have big fat pots of profit easy to tax, and it seems right that they contribute (though apparently not if they dont make a profit), however its not without consequence.
Regardless of the rate of tax, big corporates are very adept of paying no or next to no tax through their lovable tax dodging accountants coming up with wizard schemes.
We already have one of the lowest rates of CT in the developed world.