Not sure I understand fully your issues.
I would do things one at a time, maybe use a page at a time to see how the whole system behaves. I have no issues such as this and use quite a few screens (a mixture of old DXn, EXN and now DX-3 units with SIM module.
You can use a single page an had lots of elements one coming after the other. In fact I use the Slide Element to show pictures stored in a single folder. I don't use different pictures from different directories although this shouldn't be a problem.
Bill