Yes there is something you can do to help yourself.
Start from a Template. Save as .docx, then in Finder open that file in Pages - it should open and look the same. Close the .docx. If all went well edit the Template, and as you go keep exporting / importing to check it is still working.
If you check microsoft's advice how to export to .pages they give the same advice (from word templates).
Your document format is what is causing the problem - the converter is tripping over something.
I am new to these versions myself and have some spacing (layout) issues I'm unsure how are best handle.
> no one knows it's plans
Except me and others, from years of coding, we dont need to see the plans to know what they do.
The plan is not to crash. However Pages and Word frequently change, their format does as well, and it's continually a problem for programmers to bridge the two. It's been a problem since the 1980's for both so it's nothing new.
There are things one editor supports the other doesn't (avoid these) - however crashes often occur when converting fonts to fit the converted spaces, because any small mistake with a font causes a crash. Start with font Arial, Times, Courier (ones that both have). Advance to others when your preening your final cut.