...due to/as a result of/because of many people owning guns (noun + verb -ing + noun)

For the sentence,

"There is a lot of gun violence in America due to/as a result of/because of many Americans owning guns"

Don't mind the political statement :)

I'm hoping to teach my students how to use "due to", "as a result of" and "because of". If I'm not wrong, they are all complex prepositions. Feel free to correct me at any time. And I want to teach them about what follows such prepositions. I believe you can follow prepositions with:
1) nouns - E.g. There is a lot of gun violence in America due to liberal gun laws.
2) the fact that + clause - E.g. There is a lot of gun violence in America due to the fact that many Americans own guns.
3) I also know that you can follow a preposition with a verb -ing. I think this sentence is OK "He made me happy as a result of surprising me on my birthday".

Taking the gun violence sentence above, it wouldn't really make sense to say "There is a lot of gun violence in America due to owning guns". However, it seems to be OK to say "There is a lot of gun violence in America due to PEOPLE owning guns".

So my question is if it's also a rule that you follow a preposition not only with "verb -ing" but also with "noun/subject + verb-ing" as in the above case - "people + owning"?

Thanks. If anyone can explain the above use and rules, that would be awesome.