I'd like to help, but your math doesn't add up:
I have been blessed with a baby boy the very first year of marriage who is about 4 years now.
1st year of marriage, + 4 year old boy, = 5 years. Your message says you've been married for 7 years. Either the boy is 6 years old, or you've been married for only 5 years. Which one is it?
I feel sorry as he has never been honest, open or happy with me, zero intimacy, never shares information about finances, never shares any plan, never talks to me, excepts with one word answers to my questions, who is easily angered if I ask him for anything
So why did you marry such a person?
What options do I have to continue in US, I don't wish to go back to my home country and/or get stone pelted by his relatives ?
If you are a US Citizen, you have lots of options and shouldn't be worried if he "abandons" you.
I have been told that I will be moved to a women's shelter (as we live in rented house) and separated from my child, if I complain to the police ?
Nonsense. However, why do you need to complain to the police?
What would you do with a husband who does not like you or let alone not willing to sleep with you, does not provide for you and unless you bring money from home ?
You can divorce him. However, he slept with you at least once, since you have a baby for him. So maybe you need to stay calm and try to work on the marriage to make everything like the "honeymoon" period (when you were making your son with him)
What should I do if he abandon's me, quits his job and live the country (we are US citizens) ?
You can continue to stay and (depending on the state you live in) you can file for child or "family" support. However, you can only do this if he doesn't take your child with him. If you file for divorce you might be able to request the court to prevent your son from being taken out of the United States, however be aware that this is very difficult to do without getting the court involved and also if your son has dual citizenship (and therefore a foreign passport that you might be unaware of its existence). Search on the state department's website (it's something like "travel dot state dot gov", but replace the "dot" with "." and no spaces) for "prevent a possible abduction" and read it carefully.
As there are way to trace hidden savings in other countries, possibly done as bank transfers through different banks (unfortunately I don't have) possibly in the names of siblings/MIL ?
No. If the names are in names of siblings or MIL, then the accounts are considered under their ownership and they are entitled to privacy. So even if your brother or sister's wife or husband files to divorce their spouse, they will be unable to view your accounts since you are entitled to privacy from your sibling's spouse(s). Hope that explains it
TL;DR: could you try to work on your marriage instead of the drama of suspecting your husband of planning to abandon you? There appears to be no evidence so far that this is his plan