My question involves insurance law for the state of: iowa

So my father passed recently, he was widowed, so his legal heirs according to Iowa law are my younger brother and I. We have a step brother also from my mom's side. My younger brother has issues, he is not mentally capable of dealing with any of this stuff. He is homeless, doesnt have a phone, has mental issues and drug problems.l, so insurance companies wouldnt even have a way to get ahold of him. On top of that, both me and my father have no contact orders against him.

My dad and I decided to remove my younger brother from the insurance policies leaving me as the sole beneficiary. My step brother may have been on them, he claims my mom made him the head benenficiary, doesn't make sense that my mom would have control over my father's policies but anyways, if my dad removed my step brother, he did it without my knowledge.

So far I have inherited all of the policies. According to Iowa law, step children are not entitled to inherit anything. My step brother is rich compared to me. He was never there for my dad, always talked down about him and my mom for her mental issues. I lived with my dad until I was 29. I am 32 now but I have been there for him for anything he needed. I considered him a good friend and was in constant contact with him and took care of him as best I could with my full time work schedule and kids. I had a little help from one of my friends but rarely from my step brother.

Anyways, I told my step brother that I am keeping the insurance money for myself since it's all entitled to me. I told him I would split the small estate with him and give him the cash value on the two insurance policies my father had on us, which is about $2,000, and about another 7 or 8 thousand for half of what's left of the estate after his debt is paid.

He became irate. He's accusing me of making my dad remove him from the life insurance policies and saying he is going to sue me.

After doing some reading, it looks like he would have to prove my dad wasn't mentally capable of understanding what he was signing and would have to prove I had undue influence over him. Well my dad was just fine mentally and as far as influence, I didnt have any undue influence but I was definitely a thousand times closer to my father than my step brother was.

This should be an open and close case, correct? I don't think he stands a chance.

But if it does go to court it will be quite a burden on me. So my main concern is would I be able to counter sue for court costs and lawyer fees, and lost wages for time off work? It's only been a month since my father's death and I am still grieving, would pain and suffering also be a possibility for him putting me through this type of burden while I'm still grieving?

It's just aggravating knowing he did next to nothing for my father while I did literally everything, him and his wife are rich and buying two condos, have 4 cars and a boat, while I rent a house and finally for the first time in my life got a decent car with my tax return, and my girlfriend drives my son around in a rust bucket van, and he wants the money that's entitled to me. Ugh.