Would it be possible to create custom android rom to use Jolla as android phone?
As said probably yes , but i think its actually stupid. like why not buy an Nexus 4 \ Nexus 5 for a cheaper price and already have a native android?
A thing to think...
Definetly yes. The Jolla phone uses Android compatible hardware, which can be 'talked' to using Jolla's libhybris and the bootloader can be unlocked via the Recovery menu.