I'm aware of this and I've made a conscious decision to use the lazy pronunciation. I'm actually thinking of switching to lazy pronunciation as the standard pronunciation for a lot of words, the same as what some authors have done. It's more difficult and weird to teach people a pronunciation that not many people are using. At this point the lazy pronunciation has pretty much dominated the normal language development.

我都打詠春。喺學院，我師傅同埋我哋都話"lim". 如果你話"nim"會係好奇怪。我推介你試吓明粵卷唔使係一百%啱。如果係八十到九十%啱同大部分人明你講乜嘢，我覺得OK。學生可以繼續學廣東話。越來越好。

I agree 100% to use the lazy pronunciation. I'm a native speaker, and I don't think I've ever heard the formal except when talking to others who are trying to learn Cantonese.

I cannot corroborate the experience of the other commenter. 念 is very definitively nim6, with lim6 as a common variant/lazy pronunciation. It is not at all uncommon that words have a variant pronunciation when used in certain contexts (e.g. as jargon or slang), such as Wing Chun in your case, but the word itself is certainly not properly or even commonly pronounced the "lazy" way otherwise (c.f. 執念 zap1nim6; 萬念俱灰 maan6nim6keoi1fui1; 惡念 ok3nim6).

There are many cases where variant pronunciations sound natural, but (individually) "correct" pronunciations sound unnatural (e.g. 土瓜灣 tou2gwaa1waan1 "correct" but unnatural, tou2gwaa1waan4 "variant" and natural). I have never encountered a case where a correct pronunciation would be unnatural where "lazy" pronunciations would be natural.

On another note, your Cantonese sounds a bit unnatural (without many of the connecting words between thoughts) (typical for learners). A more natural phrasing might be something like this: 我打詠春嘅。學院(?)入面我師父同我哋都係讀lim嘅。反而如果有人讀nim會好奇怪。我想你明白粵卷唔使百分百啱晒嘅。講嘢可能淨係使啱八成到九成，大部份人都明你講嘅嘢。咁都OK嘅。學廣東話嘅學生可以多啲地方繼續學廣東話就可以越來越好。

A few notes on your usage:

"我都打詠春" 都 here seems unnecessary, as you have not discussed 詠春 previously.

"學院" slightly dubious, usually used for more academic purposes. For martial arts, 館 or 武館 may be more typical, but I suppose it is possible that your school brands itself as 學院.

"我師傅" "師傅" and "師父" sound the same, but mean quite different things. 師傅 is a polite name for someone working in some field, but 師父 is your master. (In fact this is another example of "lazy" or variant pronunciations, which is emphatically not always the correct pronunciation; 父 here is fu2, but by itself is definitively fu6)

"都話"lim"" "話" probably refers more to the topic of what someone says rather than the pronunciation, which the word "讀" would make clear, that we discuss pronunciation

"我推介你試吓明粵卷唔使係一百%啱" too be honest I'm not completely sure what this sentence means. I hope what I put was what you intended.

"一百%" 百分百 is more natural

"八十到九十%" 八成到九成 (lit. 8 10%s to 9 10%s) is more natural

"明你講乜嘢" (sounds like: understand what on earth you're saying) "乜嘢" emphasises the object like a question (i.e. sounds like a rhetorical question; when not a question, usually would be used when expressing frustration/complaining/scolding); no need to emphasise, "明你講嘅嘢" would be fine.

"學生可以繼續學廣東話。越來越好。" disjointed sentences, not completely sure your intended meaning. I hope what I put was what you intended.

Most of these corrections seem stylistic / "I would say it this way to make it clear" rather than actual mistakes.

Yes, I have mainly put awkward usages in the latter section, which will hopefully be useful to the author. If you compare the paragraphs, the outright grammatical problems I simply fixed. The author’s language is definitely comprehensible to a patient listener, but it can be much better still.

Thank you for the corrections, I definitely agree that while I've learned a lot of Cantonese in the past 11 years, I still have a long way to go and loving the process. Given that Cantonese is my third language (I've studied a bunch of other languages, but Cantonese is third language I'm actually specializing in for personal reasons), it makes sense that it sounds unnatural, at least for now. For a portion of it I do agree with the other commenter that it is a stylistic choice. The % part is just me using what's already popular in Cantonese speaking which is to use the "pou-cent" type of style rather than the more traditional way. You are right regarding 學院, my school advertises itself in this way hence my usage of it ;D. But overall, you got what I was trying to say which is the most important part of the process, I'll continue to improve over time :).

In my 10 years in HK, including months worth of weekly language classes, “n” and “l” were treated utterly interchangeably. Not to say that it’s not worth the effort in some contexts to make a distinction, but if the aim is to get a functional understanding of the language the “lazy” version is useful.

A counterexample for you: 聶 nip6, never lip6. 獵 lip6, never nip6. 焫 naat3, "lazily" laat3. 辣 laat6, never naat6. (Yes, almost everywhere interchangeable)

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