1. Which one is a better place for a romantic, relaxed holiday(1 week) for a couple?

Turkey, hands down! But I do love Egfypt and have lived in both places.

2. Which one is closer to Qatar?

It takes 3 hrs to get to Cairo around 4 1/2 for Istanbul.

3. Which one is safer?

Cairo is safer than Istanbul. But there isn't a huge difference. These are two very safe locations. Pickpockets are few and far between and you can easily go out at night without worries. The only issue is being overcharged. This is more rampant in Egypt than Turkey. Then again, Egypt is a cheaper location overall.

4. Which one is easier for visa on arrival for Indians?

I don't have an answer for this one. I'd check with their embassies.

5. Which one is less expensive?

Cairo is less expensive. However, quality is not usually at the same standard with Istanbul.

6. Which one has better weather?

That depends on the season. Turkey isn't as scorching hot as Egypt in the summer months. In the winter months, Egypt is warmer than Turkey. However, I would still avoid the major cities in Egypt during the winter because it does rain. This means that streets are full of mud and water. If you are visting the Red sea coast or the Mediterranean coast in Turkey, you can find nice spots even during the winter.

Also one last question somewhat related to this- if I'm on a visit visa in Qatar is that only single entry or is it a multiple entry- can I go for a holiday and come back to Qatar or not?

It should be written on your Qatar visa. If not, you can also check with immigration.

****Disclaimer: I don't want to seem like I am down on traveling to Egypt. I would recommend that you travel to both Turkey and Egypt! However, if you need a relaxing week for couples, Turkey is more guaranteed to please. Even on rainy days!