Personally, I can not tell whether I like the design of the landing gears. So much complicated and so many parts involved.
About your question, I would say that they are pretty much stable once they were installed.
However, installation would be a bit troublesome if glues, which need dry time, are used.
I use instant glues in 99% of my building. I could position the parts and done.
About the strength of the strut, the upper wide body of the strut has frames so that there would be no big issue. I have concerns on the neck (a curved section near the piston connection) though. That section has nothing in it. Mechanically, all the weight of the plane would be on it and it could be buckled with over pressure. I just reinforced inside with an instant glue with low viscosity (thin instant glue), which smears into the fiber of the paper instantly and make paper hardened like plastics. I use it when I build the frame and need to harden parts.