There is no "1 gallon per shrimp rule." You can have around 10 Neocaridina per gallon of water without any problems if the tank is healthy and you know what you're doing. Shrimp don't need much space, food, or oxygen and can do fine with fluctuating temperatures. Unless you're room is really cold, they don't even need a heater because they do best around 70-72 degrees. Of course, it's best to err on the safe side though.
Ghost shrimp also aren't necessarily more delicate than cherry shrimp. Generally, they're hardier. The problem is that most ghost shrimp are actually brackish, and because they've been raised as feeder they're already unhealthy and dying when you get them.
As for the guy saying that the nitrogen cycle doesn't happen in 1 gallon tanks, the nitrogen cycle is nothing more than the growth of beneficial bacteria. There is nothing stopping a small tank from having nitrifying bacteria. They will grow on the sides of the tank, the substrate, the plants, etc. It's just that a small tank will grow a lot less bacteria than a bigger one. Put in a cycle though and there's nothing stopping it from cycling.