Looks like there are a couple issues with this definition. First, like you said, you need to get the FamilyType, not the Name (string). I would recommend just using the Clockwork node Element.Type, but you could also convert the string using FamilyType.ByName.
The second issue you mention (input types not matching) happens because FamilyInstance.ByPoint does not like to take sublists, which is happening in your list of points. You can still use FamilyInstance.ByPoint via List.Combine.
You will also need to match your lists in length before you combine them (note the Combine by Map group). I have done this several times and it typically looks like this:
There might be a more efficient way to do this, but I have found this works well for my purposes.