I have a lot of questions regarding intersect marriage
I am male (from Sunni sect) and want to marry a girl (from shia sect). I just want to know:
1- If we (both) make compromises on our beliefs in order to minimize the differences, is it allowable? Like praying style, fast timings, and so, so can we do?

2-And it is okay to make a relation like a combination of both sects? I mean we (both) will be helping each other to minimize (not completely remove) the differences. Are we allowed to do that?

3-If we succeeded in marrying (in Sha ALLAH we will) so can we nurture our children they way we want(regarding sect issues)?

4-There are some majors issues regarding the times/eras of the following persons : Umar ibne khattab, uthman, abu bakr, fatima, ayesha.. (May ALLAH be pleased with them) so if we take out the discussion regarding these men and women’s misconceptions and tell our child to let Allah (swt) and His messenger Muhammad (saww) deal with what happened back then. And Allah and His messenger knows the best. And keep praying and making ourselves and try to make peace in society.
Is this possible? If yes, can you help me with the various verses or ahadiths or any other authentic sources.

1- For prayers, it is not possible, as there are differences in how to pray, and what to recite, and how it is recited, while for fasting, it is possible, if you will delay you break fast 10 minutes.
Regarding the start and the end of the month, she can not follow you as well.
2- Refer to 1
3- Yes.
4- There is need to get deeply in these issues.
If you want to read about this, you can refer to the book (Then I Was Guided) written by Mohammad Tejani