I'm really not seeing the whole 'will have free will, but won't sin' thing. Unless God removes the parts of our minds/personalities that makes us desirous of another's possessions, even if they be abstract ones like wife or husband, we will have temptation, if there is social interaction. And while I can see the whole 'wiser so we don't sin' thing, in the sense of us knowing it's a bad idea for a variety of reasons, and never acting on it and setting the thought aside and blah, if I remember right, having that desire in the first place, is sin.
Also
PLANTS HAVE FEELINGS TOO YOU MURDERER THEY REACT TO STIMULI AND GROW BETTER TO MUSIC HOW DARE YOU
Also, I have to wonder whether Trans people would get have their body or their brain chemistry changed to fit the other. Because there is some evidence that it has to do with hormone imbalances during gestation. When and how much testosterone you receive in the womb. Brain has a map of the body, see, and dysphasia is basically when the map of the body and the actual body don't match up, so the parts that are there that "shouldn't" be feel alien, while the parts that aren't there feel missing. It's like ghost limbs for people who've lost a limb, but sorta in the other direction. To some extent this applies to masculine/feminine and gender identification. As someone's gender is a fairly large chunk of their identity, if not necessarily their personality (though personality being the same either way would be...odd, to most people, I have to wonder which one would get 'fixed'.
I will say this is defense of it though.
@Frumple: Someone who is an asshole has an intervention and learns to stop being an asshole. This is also personality mangling, but I would also argue that it is not a bad thing. You are currently making a Noncentral Fallacy, and while I am not trying to attack you, I feel I must point it out. Martin Luther King Jr. was a criminal. He was just the good kind of criminal. What are the aspects of personality mangling that make it bad? Would those apply to the life without sin imagining of heaven? I can easily imagine it in a lesser form, with more of a 'you have more self-control, willpower, and wisdom, so everyone is able to refrain from sin and resist temptation with ease' with the obvious caveat that if you're the type of person who would sin on their own (truly sin, not bullshit 'fall in love with wrong people stuff' here, let's not argue in bad faith here), you're kinda not getting into heaven in the first place.
I mean, I'm fairly generous, but I can see why God would keep those sorts out. The rest of the bits of the bible are just to try to make sure people can do their best to understand how to become close to God, because that is an end-goal in and of itself for Him. And if you go with the whole annihilation idea, which is the most merciful He can be, if you squint and look at it sideways, then it fits neatly. Plenty of ways for it to be self-consistent. Taking the 2000 year old book written by hundreds of different people at vastly varying times with bits and pieces added or taken out as it suited the fancy of the first blokes to keep copying it down, and that's all before the translation, literally and exactly in all aspects forever, is not one of those ways.
In all honesty, though, I'm shooting for immortality in this life, not the next. Nanomachines, son.