I have more information now after speaking with my attorney. I chose her specifically because she specializes in citizenships. PM if you’d like her contact information.
What I previously said about children being able to be included with a parents citizenship application was incorrect.
With that said, once one parent has citizenship, you can apply for citizenship for your children and spouse. For children, assuming they’re under 18, there is no language or education requirement. For your spouse, as of October 2020, if you’ve been married for 6 or more years, there is no required connection to Portugal or language requirement.
The only real advantage of the child/spouse getting the golden visa is that they can get their citizenship sooner. It’s up to you to determine what the real benefit of that is. Before they are citizens, if you are a citizen, they have the right to live in the country with you though you will have to get an appropriate visa (D6 I believe) and residence permit (which is much lower cost than the GV family reunification). Before you are a citizen, if you want to all live in country, they’d have to apply for another type of visa, such as a D7 or do the GV family reunification.
Personally, after consideration, I’ve decided to only do the GV for me and NOT include my child or spouse. If we decide to live there before I receive my citizenship, they will get a D7. Once I receive my citizenship, we will immediately apply for their citizenship. This will save us approximately 20K EUR in government fees and also means that only I will have to travel to Portugal for fingerprints (as well as subsequent minimum stay requirements).