Patching Daggerfall? Impossible! Might as well squeeze blood out of a rock. :)

They are and have sadly been polluted for some years now. Personally I don't care all that much either as I expect every software to be like a Swiss cheese, no matter what state the devs proclaim the software to be in.

An alpha version of engine mod for an old game that was buggy to being with is buggy? Well, colour me shocked.

Not much different than public BETA. Alpha build should never see release, and BETA builds only rarely. The term they are really looking for is RC (Release Candidate) which, as you know is the end of the BETA cycle after extensive testing. Now AAA games release their early to mid BETAs at launch.

I do think free, fan-made projects should be given some leeway with the releases though. In the end, this kind of small projects seeks a bit more publicity so that they'd see if there even is a genuine interest towards them and perhaps find some other people who'd be willing to do some stuff.

lol

This. You can'r really expect professional polish on a fan project,,they just don't have the resources or money to do that.
Now if they make you pay for it,it becomes a professional game and professional standards apply.
AN example of a fan project gone professional is "Black Mesa" which started as a fan remake mod of "Half Lfie" but got picked up , and I suspect, partially supported b y Valve, and it costs 20 bucks.I would be lot less tolerant of bugs in "BLack Mesa" then I would for "Daggerfall:Unity"
But one big question:Is that damn rat at the beginning as hard to kill as in the original?

Forget the rat, that imp is instant death!!

Man, so many rants here...

The engine is in good shape, bug fixing didn't wait for alpha stage to begin, it was done all along. Alpha just means it reached feature parity with the original. By the way the engine is a remake so it doesn't have to inherit classic bugs, it fixes numerous issues already.
They're still bugs though, and the most obvious and annoying ones come from classic quests, they're being worked on. To give a recent example, "monsters clearing" quests: https://forums.dfworkshop.net/viewtopic.php?f=25&t=2445. But the engine had to be close to complete first.
Current alpha is publicly available because it's an open source project, so everything is public. Comparing that to commercial games practices makes little sense.

Plain Daggerfall Unity tries to stay faithful to the original, "only" adding modern systems compatibility, bug fixes, quality of life incremental improvements and moddability. Expect old school hard gameplay.
Anything else, newer interfaces, casualization, belongs to mods domain.

Open beta = unfinished.

Open alpha = doubly unfinished. Daggerfall is borderline unplayable. Working as intended.