So the princess could be his wife in the previous life?

No the princess is a seer, according to normal time line she ended up marry seika through arrange marriage but because she start to work to become better wife for him the future she saw slowly go0 away

If the princess is not his wife then it's not intresting. For some reason I don't like the hero girl

I agree with you, the hero girl is so annoying and bossy yet troublesome. I hope she move on from mc for good,i don't like she become fl why can't she just die or move to other country.