Do the smaller globes have any problem with water flow?
Nope, not that I can see. Shrimp are occasionally inside and there aren't any problems with the plants that are in there either. The bowl came with a complex system of pipes that attached to a canister filter, but I chose not to use them. Haven't had any problems so far. I do change the water every couple weeks enough to drain and refill the smaller globes.
The moss and pennywort have grown quite a lot over the past couple months. I'll try to get some updated pics sometime this week.