Shavings have interesting properties in hooking up with each other. A strong wind can blow them around, but I spread them in my garden as mulch and they clearly want to stay in place. A little care while you work should keep them under control.

Sawing by hand is much more pleasant to bystanders ears, and should keep you in better graces with your neighbors. Handsaws seem to produce less dust too. Stay away from the edges of your deck, avoid windy days, and sweep up when you finish a cut and sawing should present no problems.

Fine chisel work like mortice and dovetails shouldn’t pose a problem either. Any chips will stay close at hand and be easy to control.

The place I think you will have a problem is using a chisel and hammer or a hatchet to quickly remove waste when taking a piece down to size. I find the chips from these operations fly randomly about, sometimes traveling quite a distance. For this, I’d suggest some form of screening. Perhaps a roll down bamboo screen that would also shade your porch? Or maybe hang a drop cloth around your bench area when you’re performing these tasks.

Bottom line, I’d stay away from power tools, but I think hand tools should work well with just a little thought and preparation.

I dont think you should worry about chips and shavings. As high up as you are it will take ten years to get the pile up to interferance heigh now the folks downstairs are a different problem.
Maybe hang a tarp or blanket over the railing to slow the passage and help contain the debris