Hi Shane,
1st question/issue
You're doing it right replacing the Out Of the Box (OOB) SharePoint web part with QA's (QWP) web parts.
When it comes to the point where you need to hide the OOB New Form this is how I do it:
– put the page in Edit mode
– drop qListForm on the page
– go to the OOB New Form wp and hit "Edit Web Part" option from the web part drop down menu (verb) then go to the Laypout section and check the Hidden option, then hit Ok
Please note that you have already configured the qListForm and you have required fields on the form then this operation fails, you need to fill in the required fields and then set the OOB wp to Hidden.
2nd issue
You need to use the session so you pass the parent item ID to the child when you create a child item.
First I'd suggest you to get familiar with the session feature usage (see the docs) then follow these steps:
– I have 2 lists, Languages (LanguageID) and Countries (Country, Language). The relation Parent-Child is done through the field Language.
The scenario is the following, I want to display the list of languages and all the countries where these languages are spoken, so my parent list is Languages and y child list is Countries.
When you configure the qListView set the session for the list Languages and give it the name LanguageSession.
On the New Form page of the list Countries, replace the OOB wp with qListForm and set up the wp to create a New Item.
Add all the fields including the field Language (of the list Countries) and hit the Edit button next to the field.
Then scroll all the way down and set the Field Type to "Consume value from a session"
Use the button New Session, add the name LanguageSession, the site url and the list name (Languages)
Then set the property "Consume Session Display Field Name" to LanguageID.
Save the wp properties and try it.
If you still have difficulties with this please let me know.