All the questions you are asking are coming from your head and not your heart!
With wife and kids you want to follow your heart as long as your head (life situation) can support it.
If you would want to love your kids and be there for them, have them whenever you can. Nothing is guaranteed for anyone. Make your best case effort and love them from the bottom of your heart.
Don't seek out wife like an agenda. That is a receipt for disaster. I married my wife because that was the first person I met where my thought process was: "How can I make her happy" not "How does this person fulfill my image and needs from a life partner".
Your expectations from your life partner might change with time. If you start with a baseline and it doesn't hold anymore, it would likely lead to discontent and possibly separation. Expectation is the bane of all relationship.
For immediate family just focus on what you can give and don't expect anything back.
Maybe it would be better to seek a young wife then if you plan to be ambitious?