KasiCair
There are a lot of things I don't understand with Rei's company. The kage must by now know that the company was born in the land of water, so even if it expands and builds several offices in each country, all the kages will know that the origin of this company is in the land of water. The second point is the lack of knowledge about who the owner is. The company bears the name of Biri Biri but the shinobi are good at obtaining information and they will find that Biri Biri only owns a small part of the company, while the real owner is unknown and whenever there is hidden information the shinobi they will feel the need to discover the truth, if only for their own safety. Another uncertain point is the seals. Can they be copied? No one has ever managed to replicate the Hirashin jutsu despite Minato throwing his Kunai in every corner, so I guess that won't be possible, or maybe the odds are very low. In any case, Rei's seals are more complex and advanced even than Hirashin fuinjutsu and therefore I doubt that Kushina will be able to break them too, but there should be consequences if a country manages to replicate a company product ... like, we sell more our fuinjutsu. Finally, do you really think that the other villages will not try to manipulate the company to acquire its loyalty? All they have to do is send shinobi disguised as shinobi from other villages. This strategy worked to manipulate villages against each other, why shouldn't it work against a simple company? I wish ROOT would be caught doing just that, and as a reward Rei asks the Hokage to use Tsunade as her personal maid for the rest of the war. It would be an easy way to combine business with pleasure, with Tsunade helping the village by staying close to Rei. Finally I hope that the Hirashin jutsu will never be delivered to Minato. I always thought that the Jutsu Hirashin should belong to the Senju clan and it was only after the senju disappeared that the village gained access to the library.
He should learn blacksmithing so he can make better things himself and he should make shadow clones go to the land of whirlpools to rebuild it and put seals around it that no one could ever break or teleport into. And save the babyâs and small kids of the clans and all their knowledge and Justus to keep them from dieing out
He already mentioned the Uzumakis... Why not take over the Land of Waves that's currently empty due to all their deaths. Unless they're all still alive right now, in which case maybe he can offer them safe haven in return for their loyalty? Again, I'm pretty sure that by now the Uzumakis are either dead or on their way too dead though so the first is a better bet.