LOL Jill!!! You are exactly right that it is the children who need to be trained and not the puppy in this instance.
Those little boys sound so sweet, and are perfect for Ringo as he is for them. Dogs just know who special people are, and special children just know whom to trust.
Since you asked, and only because you asked, my suggestion where the girls are concerned would be to establish rules for the girls.
Ringo is a part of your life right now, and as such, should be treated with respect as you expect them to do of you, or any other of your family members. Obviously puppies have sharp teeth and claws, and must be watched so they don't accidentally scratch or nip as that can hurt, even though no harm is intended.
The very first thing I tell a child who is scared of dogs or over reacts to them is to keep their hands at their sides at all times. Children tend to raise their hands and their voices when they are frightened. All that signals to the pup is that they should (a) be afraid and (b) overly excited too!!! It encourages the puppy to become even more exuberant. Keeping the hands down beside their waist is key!
The other thing I do is have the children sit quietly in a circle and put the puppy in the middle. Make a game out of it as to whom can stay still the longest, or be the quietest to see whom Ringo chooses. As he learns to accept each child (and you can encourage him to "share the wealth") treat both the child and puppy to something special. It could be as simple as the "chosen child" goes first in line for something....whatever works with what you're doing...or the "chosen child" becomes your "helper" for the day. It doesn't have to be food or material rewards.
In my experience, including with my own sister and her husband, it was harder to teach the adults NOT to instill fear into the children! My BIL never had any dogs growing up, whereas my sister clearly did. She however has preferred a "pet free" life...the only one out of 6 who made such a choice. They would scoop up their sons when they were small when my Golden would approach, or my Lab! They still do it when my Cavaliers come up to them. It irritates the heck out of me, and my Mother!
My Mum doesn't tolerate it and speaks her mind, which as an SIL I can't do. Now my nephews are at least able to be in the same room with the dogs.
Once you have figured out your new living arrangements, I am confident that you will find something that is suitable for both you and Ringo as I have a strong feeling he isn't going anywhere too far away from you. I'm excited to hear how things go tomorrow with your training session as it will be more about you and less about Ringo. In no time at all, you'll have pearls of wisdom to dispense to all of those with brand new, extra young, puppies!!!
I'm pleased you are feeling better and that things seem to be falling into place. Here's hoping you find a new place, on the "ground floor" (or perhaps only 1 storey up) that allows you to do all that you wish to do. Keep us posted!