Actually, Myanmar in the past is one of the most economically developed among British Raj provinces and had the best infrastructure and educational institutions in the region (that's why one can explain why the first Asian to become UN Secretary of General is a Myanmar citizen). But after independence, they had several issue regarding discrimination against minority and political unrest because some issues. And unfortunately those issues still pervasive and lingering in Myanmar politics and society until today at large.
Yes, you're correct.
Myanmar (or Burma as it was called back then) was the breadbasket of the British Indian Raj, actually. It had provided rice and wheat to the Indian Empire and after Burma's loss to the Imperial Army in 1942, this led to the great Indian Famine that led to millions in India to starve. India was so heavily dependent on Burma's rice and wheat exports. This is a framework for us to consider in regards to Myanmar's role and potential in being a major exporter to a lucrative market (India's 1.2 billion, China's 1.4 billion and Asean's some 450 million).
Naturally after the collapse of the British Indian Empire, Burma became an independent power (afterall it did not join the Indian Empire willingly, rather fought 3 wars of resistance against the British Empire, a la the 1st, 2nd and 3rd Anglo-Burmese Wars of the mid 19th century). Reclaiming national sovereignty after almost a century of forced assimilation by the British was a prime importance for the Burmese people. So we have to bear in mind nationalistic sentiments of the day during the era of post-colonialism.
I will say one more thing. The finance sector is a massive drag factor, too. US sanctions don't help and the strict capital control laws are a hindrance. For example, foreign companies with licences can only directly repatriate 1/3 of their profits and have to find creative ways to move their money out. On top of that they have to partner with a local company though that requirement is getting relaxed. It's a real headache for these companies to come in and invest. What's encouraging though is that FDI jumped from $1B to $8B in 5 years and even before a true civilian government has come in. But yeah, the banking sector is still very primitive and accounting too as so many businesses want to keep their activities under the table.
There are various structural reforms needed in Myanmar, my friend, however what we have seen in the past 10 years is incredible in regards to growth of Myanmar's sovereign wealth and national growth. This is just the beginning , i suppose, of an economic revolution for your nation. In my view, as Myanmar grows wealthy, these ethnic and religious vagaries will be reduced. I am glad that almost every corner of ASEAN has now seen the light in .... progress-oriented development.