Mellieha is indeed lovely and is great place to live, its why we chose to live in it....it can take an hour to get to Sleima by bus on a bad day. We've lived on Malta for 4 years and in Mellieha for over three years and it has never taken an hour to drive there or Valletta. Our son lives here too and works in Sliema and on average at peak times it takes about 30-40mins drive time. There are exceptions for example in heavy storms the rain overruns the roads and causes massive delays. Mellieha has a tremendous beach and is within 10-15 mins of all the other best beaches in the North, Armier, Little Armier, Paradise Bay, Ghadiera Bay, Mistra Bay, Selmun Bay, Gnejne Bay Golden Bay and Ghejn Tuffieha too. Its also closest to the ferry port for Gozo. On the other side of the coin its is the furthest part from the city of Valletta and that can take 1-2 hrs to get to by bus depending on time of day and route taken. Our main grocery shopping is done in St Pauls Bay and Burmarrad, but for cosmopoiltan shopping we go to the city or sliema. there are other places too like Birkirkara. Jobs are not easy to get in Mellieha and you must find them elsewhere - but having said that jobs in Malta as a whole are not easy to find and when you do find one its hard to get and usually not paid well..You are lucky in that IT, Finance and I-gaming are booming work fields, so you may be lucky. Not sure what a cosmetologist is but i guess its to do with cosmetics hair and beauty stuff, there are loads of them here, id say overloaded with them.
As for Bugibba, we tried living there for 6 months and didnt like it - it was not for us. Bugibba has many advantages (its on the seafront, its busy lots of small shops, easy for accomodation, buses lots of pubs cafes bars restaurants and it buzzes at night) but for us too many disadvantages (full of tourists, dirty brash, noisy and everywhere there is dog dirt and rubbish). Qawra is ok on the outskirts nearer to the coast areas but in places similar to Bugibba.
Its only our opinion and our experiences of the places and am sure for some it suits them fully but it was not in our opinion where we wanted to live. Paceville is brash and noisy but its a fun place for the young and the young at heart to enjoy a fab nightlife but with that comes noise dirt and drunken rowdy behaviour. Some of the nice areas close by suffer as a result.
Anyway hope you find what you are looking for and good luck. Enjoy Malta.