' Is it morally acceptable to experiment on non human animals to develope products and medicines that benefit human beings?'
Thalidomide and, more recently, TBN1412 passed animal trials without any indication of problems.
Whilst in vitro testing would probably have picked up the issue with TBN1412, it would have missed the birth defects thalidomide causes. Until artificial blood becomes available for transfusions, mass scale in vitro testing using human blood and blood products isn't really possible. Blood banks have enough trouble trying to get blood without having to compete with drug companies that would pay for your blood.
Computer modelling is still in it's infancy. Though I do wonder how many compounds ruled out by animal trials will be revisited once it hits maturity.
'Do non human animals have rights ? '
I wouldn't go so far as to say rights. But as concious beings we have a duty of care over any organism we force our will upon.