Should I shield digital sensors in close proximity to one another? If so, how?
This is difficult to answer accurately without seeing the PCB layout/routing/wiring and spending a fair bit of time reading the module datasheets.
Probably the main thing to watch for is the power supply network for the sensors - for instance if you have a long looping ground return this could cause problems (use a star grounding system instead, or if on the PCB a ground plane is the ideal way to go - the distribution board you link to looks quite well designed at a glance)
Place plenty of decoupling capacitors (e.g. 1uF ceramic) near the supply pins, and ferrite beads are your friend here too (as well as power rails these can be used on data lines too to reduce the high frequency components resulting from fast rise times)
With the two RF transceivers, try and keep them apart from each other and the PCB as best you can.