Yeah I liked those episodes but they spike every now and then - they should really have tempered some of the episodes either side too so it wasn't all or nothing.
I don't agree with this assessment. I think that his growth and self-realization was portrayed in an organic and pretty much linear fashion. Neelix got his own episodes about as much as anyone not in the big three. I'm not sure what more really needed to be done to smooth out his characterization, as you seem to suggest. I certainly didn't witness the stagnation that Seven showed more than a few times, regardless of the stimulus that reasonably might have made her seem so less damned recalcitrant. Please note that I think that what was intended to be accomplished with the character did occur and that Jeri Ryan's performance throughout her run was excellent.
Those episodes only showed that Neelix was a total fake. Lwaxana actually was the person she appeared to be. The difference is she had depth also. Neelix had no depth which is why he acted like a character from a kids tv show in every single episode except for when he was called upon to do something dramatic. In those cases it felt jarring because it happened so rarely.
They'd already started to strip the layers of Lwaxana's character back by her 4th appearance in TNG's "Half A Life". Lwaxana didn't become a totally different character in that episode or later ones like "The Forsaken", "Dark Page" and "The Muse". The character development she received added to her characterisation going forward. Neelix being angry or jealous was a plot device for whatever episode called for him to act that way. It never added anything onto his characterisation. He was a dud of a character, incrediby annoying, ingratiating and came across as fake nice. That's why I hated him.
I won't comment about Lwaxana's arc in comparison as I'm pretty sure that I haven't seen at least some of the mentioned episodes. As for Neelix, I can only say that you're seeing him as a cartoon character seems like an instance of you're simply accepting what your expectations were and deciding they were fulfilled. Neelix was meant to be the breakout character of the show from the beginning. Not to overly dwell on the deficiencies of the writers or show runners, for that matter, I simply don't acknowledge that what you suggest is the strategem they would choose to accomplish their stated aim. I never found that he came across in that manner. Even before we started to become aware of the backstory that summarized so cogently the reasons we saw all the behaviors that were eventually revealed, I think there were cues that suggested why his apparent demeanor shouldn't have been accepted as it simply appeared on the surface. If you're determined to see the emphasis on certain aspects because you're resolute in not considering what was presented with a bit more discernment, I suppose there's not much more I can say to persuade you that merely accepting what you seem to have been given, is doing yourself a disservice by denying the opportunity of finding another character on the show that is eminently worth attention. Additionally, I never felt and can see nothing warranting the opinion that his friendly, open, and generous nature was anything other than genuine. He appointed a position for himself that might have seemed like hubris, but he was truly the closest thing to a ship's counselor that Voyager had, though Kes might very well have taken that responsibility if she had remained on the program.
Yeah, I didn't buy his overt niceness at all. It felt forced and even a little suspicious.
When he was normal, he was OK but they pushed the jovial comic relief angle too much and then just when you were close to buying it, they'd ruin it by suddenly making him incongruently temperamental to the point that it became uncomfortable and even menacing.
I agree it wasn't incremental or done with any subtlety.
He's fluffy mister jovial then bam!... He's the hate filled, angst-ridden wreck of "Jetrel", spewing out vitriol.
Back to soft, happy, jolly, lovely Neelix again then bam!.. He's frothing at the mouth with an angry, unpleasant jealously towards Kes in " Twisted."
Back to smiley, upbeat avuncular Neelix then bam!... He's losing his shit in "Mortal Coil" aggressively demanding answers about the great beyond.
And so on and so forth.
It wasn't handled brilliantly and did feel jarring.
Well, if you take Wang's word for it, these inconsistencies that you are citing would be easy to explain. Wang's oft stated pronouncement that the crew was instructed to be pretty much emotionless, while the aliens were the ones that would emotional color to the program, would simply make credible that we would see the latter act like genuine humans, with realistic peaks and valleys that one couldn't count on happening in regular, or logical, progressions. I don't think any other member of the cast has ever validated hearing that dictum from TPTB. However, I would suggest that there very well might be a kernel of reality in that contention. Not that Neelix was being shown engaged on a course to be more human. But I think that more than most of the cast there was a definite effort to allow him to reach an increasing stage of self-realization. It was a long process and just as with a human was, I believe, not meant to be portrayed as a smooth or painless journey. For me, that fact made his transition more feelingly executed and compelling to observe. I think for the most part, that his tempermental displays were much more evident early on, but citing Mortal Coil is instructive, as far from being a marker of inconsistency, it presents someone dealing with an existential crisis that results in a deep questioning of all the cultural norms and personal hopes that Neelix possessed to make the prospect of an afterlife, a welcoming balm to all the tumult and grief his life had accumulated. At any rate, I can't say that I ever found his pique coming across as truly menacing, volatile yes, but not absolutely out of control that he could plausibly be considered a character that would truly wish to do anyone real and unalterable harm.