Check out the main gambling companies in Gib, eg BWinParty, Mansion, William Hill, BetVictor etc
There is a list on the govt website of the ones who have a license so just take it from there. They do hire from abroad, especially if you have languages, but I've no idea about the level of assistance for either EU or non-EU countries.
when I've looked at the sites, BWin Party seemed pretty tech orientated, so you may want to start there. It's also probably the biggest.
Living costs? Probably dearer than Turkey, cheaper than the UK, for example.
Flat rental with a legitimate contact (needed to get ID) from £700 a month. Cigarettes and spirits are cheap, veg are cheaper at the local shops than Morrisons, it really depends on your lifestyle.
Our rates and community charge for the block are cheap because we have a small flat. Electricity is comparatively expensive. Fuel is cheaper than it is in Spain. The bus is free for Gib residents (ID card needed). etc etc