Hi Pete
Welcome to the forum, i'm sure you won't be disappointed in your first trip to
icmeler and turkey.
As for your questions:
Yes i would choose BB or even just self catering over All inclusive. There are lots of fantastic restaurants in turkey that you could easily try a different one for every day that you are there. Also with self catering you are able to do as you wish and have the facilities for if you fancy breakfast in the room etc. For me the use of a fridge is most important and why we tend to choose self catering over the other options.
As for the cost of a meal out, my grandparents have just come back and said that most places the prices are still pretty good. There was a chinese restaurant that were offering all you could eat including a half bottle of wine for between £7 and £8 per person. The also found a restaurant called the holiday where you could have a 3 course set meal which was about 18ytl
Entertainment does tend to be in the bars rather than the hotels
When we go we hardly take any lira, in fact it's usually just what is left over from the year before. Most bars/restaurants/shops and at the market you can pay in stirling and generally they will give you a decent exchange rate. If you want to change some £s into turkish lira then the best place is the supermarket underneath the
ICR offices near to the chill bar.
Have a fantastic time, we're off there in 29 days and i can't wait