"This destination is due to start from Belfast City - Heathrow in October using a A320"
Are you actually reading this thread at all or just like the Ryanair thread making stupid guesses??
Aer Lingus will be flying out of Belfast INTERNATIONAL, not Belfast CITY.
P.S. My question from earlier was misunderstood. When EI set up the base in Belfast, will they do it right and make crews sort out own accommodation or will it be a costly hotel thing for them?