1. Markings are not hereditary
2. Jiraya has white hair but tobimaru had silver hair..., not white, just because they are similar colors doesnt mean that silver turns to white, in this theory it can also turn to black so oro could be his son, since silver/gray is equally close to white and black.
3. Chackra is not a senju trait it is an Uchiha trait, even though uzimaki's also have this.
For those who believe that jaraya is minato's father, ----- who is the mother, you would think he would show a little respect to chasing around girls, While chasing tsunade you think she might have mentioned it.
When he found minato he literally found him, mentioning he though this could be the child of prophecy he had been looking for. If he was his father then why would he say this?