In fact, it's more likely to be productive. Moderators have said before that particularly active threads are likely to get noticed by the mod team, and if they're noticed by the mod team they're more likely to be taken to the developers.
Posting 87 different threads on the same complaint likely doesn't show up on the moderator "active threads" dashboard, and probably just becomes noise among the signal; one thread growing to 87 pages is almost certainly more likely to get noticed.
I will concur with this.
The fact that I think SQEX could demonstrably do better with their QA/testing should not be taken as a measurement of flaw against other game companies; I think all game companies -- heck, nearly all software companies -- could do far better on testing. Going into embedded systems has really made me a much more firm believer in better testing practices than when I was a game dev for my day job; the vast majority of people rarely update the firmware on various devices they have, so if you are making a medical device or a diving rebreather, you really want to make sure it works. Admittedly, the consequences there -- someone potentially dies -- are far greater than with a bug in a game, but that still doesn't mean there couldn't be some improvement in test practices used across the software (and game) industry.
That said, SQEX's record of software bugs is no worse than many game companies -- and better than quite a few, even without the complexity of the online ecosystem that an MMO entails. (And their track record on fixing major bugs quickly is way better than many.)
I also concur on this. While there's a lot of benefit to a PTR in terms of providing better (or at least, more diverse) test coverage, it absolutely ruins any surprise on storyline or plot which is so key to this game's intended experience. Sure, there are things in MSQ that could have been caught in a PTR; I'm thinking of a certain solo instance which concludes with a button-mashing Active Time Maneuver that -- unlike basically every previous one -- did not lock out legitimate keyboard input at launch, thus potentially causing you to open a bajillion windows in the game rather than actually giving input to the ATM. But I think the benefit of getting to discover the story relatively naturally rather than having it spoiled outweighs those handful of situations.
And it's a fair point to note that the difficulty of splitting out just new systems or mechanical changes without including content is a significant extra effort; it is one reason that a lot of companies don't do a PTR, if they don't want to spoil story and decide the time saved and test coverage gained is not worth the expense in time and effort to make a mechanics-only public test. Honestly, I suspect it is probably a factor in why SQEX doesn't, which... I mean, I can respect that, even if I do think a PTR for testing mechanics would be of huge benefit to any MMO, this one included.