I dont get the argument of why people mining with gpus are more likely to sell them than those mining with cpus.
They aren't. But GPU mining is generally multiple times more profitable than CPU electricity cost wise. Also it's much easier to build a GPU farm than a CPU farm having an equal hashrate. People who mine with their own PC with a GPU probably will hold but GPU farm owners often take quick profits and sell their mined coins rightaway especially if the coin becomes popular and mining is profitable.
When the playing field is evened out, there isn't as much advantage to pump and dump.
Maybe, but before it evens out we may see a large price drop.
However, it can make your already mined coins more worth as now it will probably be priced for the increased hashrate/watt/dollar.
Worst thing that can happen is that factory miners will start mining hard and then drop it leaving us difficulty-locked
