If you were a kid living in the splatooniverse, then from your POV, the equivalent to hacking would be changing you ink color to "unacceptable" colors. Such as white, red, brown, black, or any others. It is only acceptable to those who are well known.
Anemones are highly aggressive, and the clown fishes are there to "keep them in check". Also their hair are highly poisonous (and they use fish mucus as if it were shampoo to keep others from touching it). if you were a squid from a POV, then the launchpads actually give you enough ink to fly towards your destination. A squid is also far sighted, so the ink that is filled with them works well. So the reason why squids cant just fly to their relatives is because they don't have a good pin point sense. This is also the reason why Cpn cuttle isn't allowed in turf wars anymore.
Waiting for more challengers in a turf war is the equivalent to just waiting. Basically, the huge tower that leads you to stages actually open up "ink tube". Where a kid can turn into a squid and swim in small tube, leading to a safe zone.
The reason why the ink turns into nothing when spread, is because of Judds analytical powers (also, his line of species and make existing things appear and disappear as well). He stresses too much on simply cleaning ink. So when your ink turns into nothing, that's just his power, which has took control over a single area, effects your weapon.
Other creatures do in fact go to turf wars. However it is not really prohibited because they don't have the same powers as squids do. (But they do have an alt form, such as Sheldon when he shrinks into his shell and p up when you zoom into his store.