Oh, absolutely, convention says that the GG doesn't refuse assent. But they do have the power to do so, and if they were presented with legislation that sought to abolish requirements for elections, or allow arbitrary executions in the streets, they would be quite entitled to refuse it assent. That it doesn't happen speaks as much to the general reasonableness of legislation that must pass through a multi-party system as it does to the power being symbolic.
And the Commander-in-Chief has similarly symbolic placement, but equally real power. You buck the chain of command when things have gone all to hell. The GG exists as a symbolic check on the power of the Legislature, but that symbolism must include some symbolic muscle. It's all theoretical, because I just cannot envisage a situation where the GG would have to mobilise the military to evict a rogue parliament, but that doesn't mean it's a scenario that should be discounted entirely.
If we do a formal constitution, and decide the GG hasn't even the symbolic power to refuse assent, then I damn well demand a bicameral legislature!
There are two things a government could do to thwart a G-G refusing assent. They could simply replace the G-G, or they could add a clause to their bill stating that it becomes law on Third Reading.
If the G-G were to attempt to take over the chain of command, again they could simply be sacked. If a soldier were to regard themselves as not subject to the chain of command, they could be tried for refusing a lawful order.
This is not entirely academic. In 1913, the British Army bucked at being ordered to coerce Ulster into an independent Ireland (which had the support of the Asquith government and a majority in the UK and the island of Ireland). The situation became moot as a result of subsequent events in mainland Europe. Had it not, there might have been conflict between loyalist and rebel soldiers. The events of 1913 (there's a whole lot more to it) are one of the failure instances in Westminster style constitutions.
In a functional democracy, all these matters are academic. But it's important to discuss them in ordinary times, because if an extraordinary time arises it's too late.
Having an entirely unchecked legislature, even if the existing checks are largely symbolic, is distinctly undesirable. That we have a unicameral legislature makes the GG's reserve powers all the more important. Note that it's a reserve power to refuse assent, not a reserve power to grant it. By definition, a reserve power is meant to be exercised sparingly.
On the chain-of-command issue, Commander-in-Chief > Minister of Defence. It's permissible, but highly irregular, for someone higher to give orders to someone who's not their immediate subordinate. If the CiC went around the Minister, that would be a theoretically legal exercise of command authority. Again, something that shouldn't be required in a functional democracy.
In which case the result wouldn't change.
First, I'm not the only voter in my electorate. Second, having that option on the ballot paper means that we can be more sure that the eventual winner has the confidence of a majority of voters; in a democracy, this is a good thing. Third, it might have changed the result in Tauranga last time; I admit, this is wild speculation, but it's a possibility.
The point of putting options on the ballot paper is that possibly they could result in something different and/or useful.
There's another conversation going on in this thread about safeguards against the unlikely event of getting a rogue government. A No Confidence option would be a safeguard against all the existing parties in parliament putting really evil candidates in your electorate. A non-incumbent independent is very unlikely to win under FPP (which we have in electorates), mainly because of self-fulfilling prophecies (like this one :) ). Condorcet elections would provide a similar safeguard, by making it very unlikely that voting honestly for your most preferred candidate will increase the liklihood that your least preferred candidate will win. A Condorcet election with a No Confidence option could guarantee that no-one wins an electorate without the confidence of at least half of the voters. In any case, it's better to introduce such a safeguard before we get a completely corrupt government, because it'll be harder afterwards.
The two options from having no confidence on the paper are the same MP or no MP, which is a terrible result.
Depending on who the MP was, it might be a better result. And if the voters prefer that result, then who are you to disagree? Why do you want to deny them the option of disagreeing with you on that question?
This is a party that got over 40% of the vote, there obviously was a fair bit of confidence in them.
Why? How do you know it wasn't fear of a Communist government that made people vote that way? Even if there was genuine confidence in that case, how do you know that fear of one party would never cause people to elect an utterly evil government? A No Confidence option can't completely eliminate this possibility, but I think it would help. And would it really be that bad if our votes were made more expressive? With a No Confidence option on the ballot paper, a vote for a candidate then expresses "This is my preferred candidate, and I genuinely have confidence in them; I'm not merely more fearful of their opponents."
I've just run an election in which some of the candidates weren't qualified to stand up at the podium, let alone do the job, and all of them were elected over the no confidence option by a mile.
Obviously the voters disagreed with you in that case.
Third, it might have changed the result in Tauranga last time; I admit, this is wild speculation, but it's a possibility.
If a signifcant bunch of people voted for Bob Clarkson as a vote against Winston Peters, the result could have changed. You might have seen those people changing their vote to no confidence.
The result however would have changed to Winston Peters getting elected. You're advocating a change in the voting system which could have resulted in a result which goes against the current will of the people - which is to have Bob Clarkson as MP over Winston.
If those people don't want Winston as their MP they are better off voting for another candidate, because that is the vote which will give them that result.
No confidence isn't about changing the results of elections. It's used as a safeguard in student elections in which there is only one candidate standing, and they're so bad that it would be better to not have the post filled and have a bielection. Even then it doesn't work. No confidence hasn't won an Otago election in over 16 years, across up to 15 positions - it's been put up about 250 times.
This is not something we have occur in general elections, parties know they'll get stung if they put up complete morons in electorates. It would never win in a general election.
A No Confidence option would be a safeguard against all the existing parties in parliament putting really evil candidates in your electorate.
A safeguard against all the parties putting up really evil candidates, is that one (or more) party will go "man, all the other political parties are putting up Satan's little helpers as their candidates. If we put up some really good candidates, we'll get craploads of votes."