No- people are free to believe what they wish and to justify their belief in any terms that suit them: they may be right or they may be wrong. However, if they attempt to justify their beliefs via a fallacy: any of them, then they commit a reasoning error. So, in relation to the NPF when used in relation to unfalsifiable claims involving divine agency then when someone says along the lines of 'and you can't show I'm wrong' then, in effect, they are clearly implying that their position is correct, since they are saying they can't be shown to be wrong - neither they nor their interlocutors is implying any 'guessing' is involved.
That was the point I made in my previous post - I disagreed with your assertion that they were attempting to justify their belief by stating 'And you can't show me I'm wrong'.
I think a theist justifies their belief based on their personal experience of what they perceive as the net benefits of their particular belief.
I think that when they say you can't disprove whatever their belief is they are just pointing that out to you. Whatever you think they are implying by that statement is just you guessing unless they confirm that that was what they were implying.
You can of course still assert that they are implying whatever you think they are implying but assertions don't count for much without evidence. Maybe a theist such as Hope or Alan or someone will come by and provide the evidence by confirming that they agree with your assertion.
On a personal note, I can confirm that I am NOT implying that I am justifying my belief by stating you can't disprove my belief, even if you want to believe as a true for you belief that I am implying that. I am just pointing out the obvious. I use personal experience to justify my belief.
No, as noted above, the NPF involves a statement along the lines of 'you can't show that I'm wrong' and doesn't get as far as either 'so we are both guessing' or 'true for me and true for you too' - the argument fails due to the NPF with the 'you can't show I'm wrong' element, although it may be that other fallacies are then deployed.
I disagree with your definition of the NPF because your definition doesn't seem logical. I don't think the NPF consists of just the statement. It can only be a fallacy if the person making that statement is justifying their belief with that statement rather than merely pointing out the obvious - that you can't disprove their belief - meanwhile their beliefs are justified by personal experience.