Well, let's look at the "this is NOT OP" bit in the opening.
Yes, fire shield could make a decent counter, for the same reason it'd be ridiculous cc if used in the same deck as this.
However bonewall & dissipation field? No.
Bonewall fails versus swarmer decks, and this would work best in a swarm deck. Dissipation field can be overwhelmed by mass damage, and a field full of 7/1 ghosts could plow through the opponent's quanta pretty quickly.
Of the other shields, thorn carapace could kill them, but not before each ghost could make at least one other ghost. Therefore if you have a boneyard thorn carapace is not much of a problem.
Hope is the only shield that can stop the full damage of these guys, and if you combine it with cc, like say . . . fire shield? Then there's little concern over hope either, as RoL only has 1 hp, firefly has 2 hp and anything bigger (gold dragon + luciferin) could just be turned into a ghost and killed by your fire shield.
The other shields might slow you down a little, but not more so (usually markedly less so) than they would a deck based around a different type of creature.
Creature control is, of course, useless since they're immaterial.
A couple last things to note: Eclipse and devourer. Eclipse turns your phantoms into 9/2 immaterial creatures. That's a serious hitter, and not overly expensive at 8
for the first one and then 2
for each one after that. Devourer on the other hand can give you the
you need for ghost's/haunted houses (which I haven't even started on) while stalling your opponent for a turn or two. And once you have ghosts in play you can just turn the devourers into more ghosts.
