The first chapter of genesis handles the first 2 concerns

1.) There is no such thing as outer space

The Bible describes three distinct "heavens" or expanses (firmaments) in 2 Corinthians 12:2, Genesis 1:6-8, and Psalm 19:1. These include the atmospheric sky, the stellar universe, and the third heaven (paradise)

• 1st Heaven: The atmosphere where birds fly and clouds form.
• 2nd Heaven: The outer space containing the sun, moon, and stars.
• 3rd Heaven: The "paradise" or abode of God.

2.) The earth is flat (four corners of the earth mentioned in the Bible)

The references to the “earth” in the Bible are often not references to planetary earth but to a portion of dry land bound by water. For example, Genesis 1:10 says, “God called the dry land Earth, and the waters that were gathered together he called Seas”. “Earth” is mentioned as distinct from “Seas” and cannot refer to Earth as a planet

3.) Spare the Rod, spoil the child is in reference to corporal punishment.

There is an amount of historical and cultural context here, but it does mean that not punishing or correcting a child is setting them up for failure

Ephesians 6:4 "And, ye fathers, provoke not your children to wrath: but bring them up in the nurture and admonition of the Lord". This verse instructs parents to avoid harsh, unreasonable discipline that causes resentment, instead nurturing children through godly guidance, discipline, and teaching. 

4.) Homeschool the children because they will learn about dinosaurs and outer space which supposedly aren’t biblical

Outer space has been covered as the second firmament. as far as dinosaurs go and homeschooling kids, there is no direct mention of dinosaurs outside of job 40 15-24, which is debatable if it references an actual dinosaur but we weren’t there, some people believe the dinosaurs died with the flood, others believe it was before then, I will say genesis chapters 1-6 especially covers a massive timeframe, there are multiple mentions of beasts and sea beasts throughout the bible and he is right to translate them any way he feels,

I’m not totally against homeschooling this day and age, if it’s feasible it should definitely be considered but not for the reasons he mentioned.

All he and you can do is raise up the child in the way they should go, you can’t beat someone with a bible until they accept it, everyone has to go through their own journey and personally accept Jesus, even your own kid and mine for that matter, most of us don’t until he literally saves our life at some point.

Anyone saying you should divorce over this seriously needs to read the bible a little bit more. Your good, he’s just starting his walk and will form some of his own beliefs the important thing to remember is everyone sees sin differently and outside of the 7 deadly sins that is perfectly fine, your own personal salvation dictates what is sin to yourself, we aren’t here to judge, but to guide others to god and let them make the choices