[hipnoizz]

I would not be so optimistic to say 99%, but I think a lot of things like that could be actually assigned to some rules that are, well, actually applied pretty consistently. E.g. isn't devoicing of 'w' in 'wszystko' just the case of clusters of voiced and voiceless consonants? Similary 'Hodów' shows devoicing consonants at the end of a word.

I'm not sure about 'ą' - some examples would handy, but if we are talking about differences due to regional accents then following rules would be perfectly fine. With 'ę' - how do you pronounce 'część' actually? Again, I think the worst that can happen normally would be to be judged as 'ą ę'* ;)

I think that in general Polish pronunciation is fairly 'regular' and with applying just a few rules you would be almost always OK. Obviously I haven't try to learn Polish as my second language.

* For non-Polish speakers - if someone is 'ą ę' it means that (among others) he/she tries to be overly 'correct' in pronunciation.

[avereveard]

Well ę in część is without the n never heard it with n, but I definitely use the n in words like jęzik, so yeah you cannot generalize between those nasals and "say n if it's in the middle of a word" only goes so far

Ą is a bit more regular at that, so usually loses the n when at the end of a word and never heard without n when in the middle of a word, except in places like Warsaw, and other cities up north, where I was called out as gòralski (which is funny considering I'm Italian, I guess I'm learning polish wrong but convincingly enough)

[hipnoizz]

My first reaction was that I would pronounce 'ę' in both 'część' and 'język' in the same way, i.e. without 'n'. But I can see that pronunciation of these words as per https://en.wiktionary.org/wiki/cz%C4%99%C5%9B%C4%87 and https://en.wiktionary.org/wiki/j%C4%99zyk disagrees. And then a quick search brought these 'simple' four rules (https://sjp.pwn.pl/poradnia/haslo/Wymowa-samoglosek-nosowych...) for pronouncing 'ą' and 'ę' in the middle of a word ;-)

So yeah, everything is easy, simple and obvious when you are a native speaker and I stand corrected :)

[avereveard]

Ah also chcesz I've no idea how to pronounce that maybe an X at the beginning and a fshhhh at the end no idea.