I want to reply as one of the people pushing the "actually, certificated
is a word" line.
I think perspective here is important. While anything that a speaker and hearer agree has meaning can be considered a word, there is definitely a separate matter of blending in to a particular linguistic context. I wouldn't deny that.
But I do think it's important to remember that what you're doing is trying to blend in to a particular linguistic context... not trying to be right instead of wrong. In some English contexts, "kindly do the needful" is a normal, unremarkable phrase. In others, it barely registers as English at all. In some, you can rent a flat when you go on holiday. In others, it's an apartment and a vacation.
Regardless of context (to my knowledge), we talk about a "building site" not a "building place", for no apparent reason.
There are no reasonable criteria by which any of those phrasings can be considered "wrong". They just don't sound natural in some (or all) contexts. But when you consider this perspective, things get muddy quickly because language usage varies so much. Like... I would say your sentence "I have noticed published mistakes myself and had private and much nicer feedback about other mistakes before." would sound more natural with "have" added... "I have noticed published mistakes myself and have had private and much nicer feedback about other mistakes before." But I can't say a native speaker would never say it the way you did, so what do we take from that? Probably any piece of writing can be improved, whether by a native or non-native speaker. At what level do we say the speaker sounds native? It's just all very muddy.
It's not even clear who gets to count as a native speaker. Is someone who grew up speaking Indian English in school but a different language at a home a native English speaker? Their accent and word choices will make very clear they aren't a native speaker from an "English speaking country" (US, UK, Canada, Australia, New Zealand), but... English is an official language of India and spoken every day by millions of people there. Is someone who grew up in Amsterdam and learned English in school from childhood and has used it extensively as an international / business / default fallback language for their entire adult life a native English speaker?
Nothing with language is black and white. If your goal is to be understood and to have the fluency to express interesting ideas with nuance and clarity, then you're already there. Are there tells that you aren't as high up on the "native" spectrum as others? Yes. But if I applied the same critical eye to my own writing after 5 years when I've forgotten it was me who wrote it, I could probably find things I would perceive as non-native there too.
So basically I'm just trying to say... your skill in English does not in any way appear to be an impediment to using the language effectively. While there are things which could make you sound more native, those aren't a matter of right or wrong English... they're a matter of word choice / phrasing that sounds more familiar to the context you are speaking into.