Spreadlove!
I completely agree with you about the correct usage of 'sa' and 'sha' in our barnamala'. Nepali language in its spoken form is quite corrupted as it is now. That correcting Indian guy was indeed right about pronouncing the word "Shanti" with a "sh".

There is only one way to pronounce each word in the Nepali language (in Hindi and Sanskrit language too, for that matter) because we have separate consonants (ka, kha, ga ...31 letters) and separate vowels (uh, aa, e, ee, u, uu, eh, ai ..12 letters) that we couple each consonant against each vowel to capture every possible sound of words in the language. Thus we get, ka kaa, ke, kee, ku, kuu....and then kha, khaa, khe, khee...and so on until the rest of the consonants get their turns. Thus again, the bottom-line is - there is one and only one way to correctly pronounce each word in Nepali, Hindi or Sanskrit. So next day, if a Indian Guy with this knowledge comes and reads the Gorkha-patra before you, he should be able to pronounce it just like Nepali-perfect you, even though he may not be able to understand every word.

Americam English language is adopted as a primary language by the immigrants from every corner of the world who had grown up writing and speaking a different mother-tongue they tend to simplify the language so that they can learn it easily. Probably that's why so many difficult or redundantly spelt British English words evolved into simpler ones- like "cheque" in British English got modified to "check" in American English. There are so many others like Colour Vs Color, Catalogue Vs Catalog. Similarly, a big chunk of the Nepali households have a tribal language other than Nepali. Therefore the ones who did not undergo proper Nepali education tend to corrupt or over-simplify the language to the point where the grammar or usage of vocabulary gets screwed up.
Even that popular song '"paani khaane nihule (or niule) timro ghar-maa aaulaa, mauka miley raani bun-maa ghumna jaaulaa...". "Paani pani katai kasaile khaanchha?, sirif paani piuchha po ta".

I have a belief that cuisine and language are two of the most authentic characteristics of any culture and tradition. Therefore, when an adopter comes along, he or she needs to start from learning the letters of the alphabet, then grammar and then go from there. That's a great foundation to build upon to learn, and preserve the authenticity of the language both in written and spoken forms. In general, even though, one might have learned to speak a new language fluently, if there is no written knowledge of the language, sooner or later that person is going to run into constant road blocks as he proceeds along.

And to each Sajhaite who spell the word "loser" as "looser", you are a loser indeed!
Just like that correction-happy Indian guy, I can't help correcting the next person once in a while.