Hi,
Me and my boyfriend (madnesstiger on the forums) went for the first time last August for a week, and are flying out for a fortnight on the 13th of this month.
As it was our first time, we went on a few of the excursions they had to offer, so will be relaxing a little more this time around. We went on a day trip to the mud baths/turtle beach which was well worth the money (even if we didnt see any turtles!). We also visited
Marmaris market on the Thursday, had a go on the jet ski in the sea, and went on the jeep safari (another recommended trip).
We found
Icmeler was about a 45mins walk from Marmaris along the seafront, which gives you a choice of 2 resorts for a start! Icmeler is the quieter of the two, although there are still plenty of bars/restaurants open all day long (often with theme nights).
To answer some of your queries from our view...
If there's only the two of you, I would say you wouldn't really need to hire a car, as taxis/minibuses pick you up from your
hotel to take you to the excursions, and if you get tired of walking to Marmaris every day, there are the dolmuses (mini buses) available for very cheap fares (about 50p i think we paid per trip). Also, i believe there's a boat you can take as an alternative. There are plenty of things to do without the need for your own car.
I can't really think of anywhere to compare Icmeler to in the UK. You could maybe compare Marmaris to a hotter/friendlier version of a typical UK resort, and Icmeler a smaller version without the McDonalds etc. There's some great scenery, and we couldn't believe how mountainous it was as to what we expected.
Erm... as for decent restaurants and the like, we enjoyed Captain Bulls**ts food (best chinese my fella's had... ever!). We were 'all inclusive' last year though and had lots of meals in the hotel so didn't eat out all that often. It's only B&B this year though as we had chance to see what was on offer last year and compare prices of meals. There are loads of restaurants available (I'm sure someone else will be able to give you further suggestions on this topic). The average 3-course meal in Icmeler seemed to work out at about £8 per person which sounds very resonable and is why we're going B&B this year.
Lastly, we changed all our English to Lira before we went last time, and will probably do the same this time too, although it looked like you could easily change money while you were there (the rates seem better there too). I think also, you have very little problems using Euro's/UK pounds for most things on offer too. Again, the more experienced of the forum members will maybe give you a better idea.

Hope this has helped a teeny weeny bit, it's just what we remember ourselves.