Hi,
This is more of a legal case than a financial matter. Though I will try to answer the questions listed above, I would suggest that you consult a lawyer as well who will be in a better positions to help and advise you.
1. What makes you think that the New firm is not formed complying with legal provisions? Though the intent of making the new firm may be dubious and the way assets were taken over can be illegal you may not be able to claim that the new firm was made in an illegal manner. You can use the argument of equal right over your father property to contest the assets taken over by the new firm. Since you were the partner in the original firm, the firm cannot be dissolved unilaterally by other partners. They need your consent to do the same.
2. Yes you can use the argument that since the new firm was not existent when the RTGS was done, there is no question of giving loan from the new firm. However, do you have any document which supports that the RTGS done was a gift? Be ready for that question if you contest in court.
3. Partnership contracts usually state where the shares go on the death of one partner, and it is usually to the other partners. However, you can contest this in the court of law as a legal heir and since you were also a partner of the old firm, you will have a right to claim your fathers share.
Hope I have been able to help you partly!