I walked the path last year, didn't encounter any problems.
The north section between Ryde and Cowes and between Cowes and Shalfleet is road & lanes. However the parts of the path (north section) has been taken of the road and run parallel with the road/lane along the field edge.
Campsites are a bit thin on the ground close to the path:
Stoats Farm, Freshwater.
Great Thorness campsite is expensive.
The Orchards campsite.
My favourite is Chine Farm Camping Site, Military Road.
They all Camping, Caravan and Motorhome sites
You can wild pitch if you're really careful.