I shall assume you are genuine and respond accordingly.
On linguistic cleansing, they did it by:
- removing non Mandarin Chinese languages from nearly all official media
- doing the same with entertainment, even in the cinemas
- pinyinizing all traditional foods so that they are uprooted from the roots of their origins
- calling non-Mandarin Chinese an infection (LKY, a couple of years back).
You were oddly astute when you mention the various museums; museums are places where we marvel at what has been lost. Much of the non-Mandarin culture in Singapore has been killed off and resides only in museums. I prefer to live and evolve it, rather than view its past form.
I will deal with the last 2 points together. Maybe many are not as 'strong' as you are but comfort in one's language and culture has always been a source of personal as well as communal confidence. See what happened when white people deemed native cultures in America and Australia to be inferior and tried to 'improve' them. Without this confidence, the 'Singapore identity' that is forced on us is hollow and fragile. With it, we offer what is ours and accept what other communities offer us.