You can work remotely from Kahve Dunyasi (Coffee World) locations in Kabatas, Besiktas and Nurosmaniye where you can find specialty & regular good coffees in reasonable prices with internet connectivity. You can work without being bothered and enjoy their coffee. Starbucks in Bebek is also great place for meetings right by the Bosphorus.
For top sights in istanbul, you may check www.istanbulshots.com about 5 years ago
If you looking for free of charge places, you may try salt galata research library. When you google salt galata you can find more information. That is a place in Galata, which is renovated from old Ottoman Bank to new modern art gallery. It is fully sponsored, therefore you dont need to pay for anything. You can bring your water bottle with you into library. Fast connection internet is free. about 5 years ago