Relocating in 10 days - Seeking advice on Malta

Hello there!

I'm moving to Malta soon as I accepted a job offer there.
I'm in Warsaw, so that's at least the same time zone, but different money (euro).

I'd like some advice on some stuff I can't really google out (and mind you, I've already read information disclosed on 2 forums about Malta):
- in Malta, what is considered a "good area to live in"? Also, my workplace will be in Gzira, near Empire Stadium.
(from what I heard so far, some people said Mosta and Rabbat, most people ranted about Quawra/St. Paul's/Bugibba area and St. Julian's/Sliema areas, and Gozo was often called a "God's waiting room")
- about goods in Malta, I understand there's no IKEA nor H&M and such, but it's not that bad right? It's possible to buy clothes and furniture, appliances and such? I saw many pharmacies on the map, but how about cosmetics' prices? Facial cream by Vichy for example, better bring or buy upon arrival?
- about life, I read there are many pubs, but most are rip-offs for foreigners. Is it only in the less touristy areas (or the contrary?)? Are there any cool places to hang out, preferably without the touristy "glory"?
- upon arrival, what ever the things you regretted not taking or not doing? I'm a rather seasoned traveller, but Malta is a small island, so I'm thinking it might be peculiar. So far I've never lived in a city that small, rather dwelled in the ridiculously big ones.
- about credit cards, you'd say it's rather common or uncommon to use them? Do stores accept them or is it more of a cash society?
- on one forum it was mentioned that due to the lack of central heating it can get pretty cold in the apartments mid-winter - is obtaining a heater a problem? Do landlords provide these kind of stuff?
- lastly, apart of the power yoga recommended somewhere in this forum, is there any gym you would personally recommend? I like water, so pool would be nice, but saunas are more important. Most of what I've seen was the rather expensive luxury hotel properties.

I think that's all for now, I'm bugging my friends network at the same time to get the most information I can before the departure.

I hope to meet the Maltese expats soon :)
Greetings from Warsaw!