Packing peanuts actually do more harm than good. They are hydrophobic so repel water. Making the potting mix less likely to drain properly. This is also compounded by having large air spaces at the bottom and a mix with finer air spaces above it. This causes a zone above the large spaces that holds water more.

They also reduce the depth of the root zone. Not generally a good plan as many cps are deep rooted, particularly Cephs with a fairly long underground stem.

Clay pots are fine for a while but they have a tendency to accumulate salts within the clay because of the evaporation from the surface. Eventually it may get to the point where roots that hit the clay stop growing as if 'burned'. How long they plants will be happy depends on alot of factors such as water quality, flushing of the potting mix and pot, rate of evaporation off the pot etc.