If GW were to not complete his term, for whatever reason, would Cheney always become pres (assuming he is alive and unimpeached himself)? (can the VP be impeached?)

On a related note, with the dissatisfaction among repubs in DC, if the US had a parliamentary system, would a non-confidence vote succeed? ie, would enough Rs vote against GW to make a majority with the Ds?

(In parliamentary systems, as in Britain, Canada, etc, if the Government in power has the majority of members of parliament vote against them, they are required to call an election immediately. This happens most often in a minority gov't situation - as with the last two elections in Canada, and probably the next - but could happen in a majority if enough members were upset with the leader's/cabinet's performance)

On another related note, if enough of their constituents wrote/phone expressing a certain opinion, would the representatives in Washington vote according to the constituents wishes?

Is there a "recall" mechanism in the US? (in BC, if 40% of the registered voters in an electoral area sign a recall petition, a by-election can be called and if the incumbent loses, they are out).