Why do you guys want to make it harder for the little ones?
Don't be a cheap ..get them a regular .40 or .60 trainer.
Bigger will fly better, slower and they can see it better.

The bigger a model is , the better you can see it. Therefore you can fly it further away from you.
Therefore the box gets bigger, Therfore the model has a greater distance to travel , therefore it'll look like it's flying slower.
Therefore it'll give newbies plenty of reaction time.

My .40 and .60 size looks same (in size) during flight becuase I simply fly the .60 further out becuase of depth perception.

A smaller model will required more air speed to fly due to wieght or wing load. A .60 trainer will float all day long
on 1/4 throttle.
If you decide to go mini or micro servo to make up for the weight, it'll cost the same if you had just gotten a .40 size.

I had an eglet. you need to maintain more air speed, plus it's only 3 channels. which will make it harder
on the little ones if you they add too much input using only rudder. Give them airlerons as you would give yourself.lol

I'd hide the glow plug driver and the fuel when I go to work..though.
You know a 7 year old is not just going to stair at it all day long.
Even if you hung it up, he'll bring it down and try to flick it with a spoon in the house.lol