Am I entitled to demand the full profits from my brothers, the partners, after the business was harmed by thefts, knowing that pursuing this right may lead to discord and estrangement?

It is better to demand your right kindly to avoid severing ties of kinship. If that is not possible, and the choice is between litigation and waiving some of your right, then it is preferable to waive it, seeking Allah's pleasure, maintaining kinship, and preventing discord, for the Prophet, peace and blessings be upon him, said: "Shall I not tell you of something better than the degree of fasting, prayer, and charity? Reconciling disputes, for discord is the shaver."

If you prioritize maintaining kinship over fully obtaining your right, this will bring abundant provision and Allah's support for you, for he, peace and blessings be upon him, said: "If you are as you say, then it is as if you are feeding them hot ashes, and you will continue to have a helper from Allah against them as long as you persist in that." And he said: "Whoever wishes that his provision be expanded and his lifespan extended, let him maintain his ties of kinship."

Therefore, waiving some of your right to maintain kinship is a treasure for your children. As for asking them to swear an oath, there is no religious impediment, but one should consider the effect of making them swear on your relationship with them.