Beamdog? Ugh. After Baldur's Gate: Siege of Dragonspear fail plus the "enhancements" to BG:EE ranging from inserting bi-polar new characters with laughably cheesy fan-fiction level "modern character writing" to
ugly as hell cell-shading that looks like a comic book floating over the screen, crashes, save-game corruption and new bugs with each new post-release patch, etc. If you don't already own the original PT now, then it's probably worth keeping a GOG offline installer of the original + working mods backed up "just in case"... As for the technical side, presumably it's just Beamdog claiming credit for repacking years worth of
other modders work again (Bigg's Widescreen + Ghostdog's UI mod + Ultimate Fixpack + Unfinished business, etc), then quintupling the price up from the usual $2.50 in GOG sales?
In fairness, they really did basically rewrite the engine from the ground up. I remember reading some technical details on how the Infinity Engine used to work, and how their engine works - it is quite different.
They have also got Chris Avellone involved because PS:T is a sacred cow that they don't want to mess with. This is why there is no new content - no new quests, or companions, or areas or anything like that.
As for the rest of your criticism of Beamdog, yeah unfortunately I mostly agree. For some reason, whenever they release a patch, or a new game, they break as much stuff as they fix. I mean, if they just introduced bugs into their own content, that would be one thing, but instead they introduce bugs into old content, which is just really dumb. In this day and age of software engineering, are you telling me it is impossible to find a technological solution that unit tests your quest triggers? I don't know, as a software engineer I find it difficult to believe that they haven't invested into tools to improve their software quality. Its quite lousy.
As for the new content they introduce.... meh. Let me give you an example.
The assassin was a class kit introduced into Baldurs Gate 2 years ago. It has a special ability, called Poison Weapon, which is extremely powerful. It adds poison damage to each attack for 5 rounds, with no save. The thing is, the assassin kit itself is just not that powerful without it. Good if you use it properly by hiding in shadows and all that, but no powerhouse.
But then they introduced the Blackguard, which is an unbalanced evil paladin. It has pretty much all of the best characteristics of other paladins, with the only caveat being it must be evil. They added poison weapon to it.
Now when you add a powerful ability that was formerly only used by a relatively normal kit, to a kit of unbalanced and unparalleled power, the result is going to be sheer cheese. Plus, their Baldurs Gate enhanced edition allowed you to use kits that were not possible in original BG, so they had poison weapon right from level 1, where it is pretty godlike.
The end result of this is that they decided to nerf poison weapon because it is too powerful in the blackguard's hands. Yes, you read that right. They added an existing ability to a new kit, realized the new ability was too powerful in the hands of that kit, so they nerfed the ability, making the assassin a lot weaker. That is the kind of logic they use when balancing stuff.