Do you need to speak Arabic? I don't speak this language, but will be happy to learn. Am mostly wondering how much I should focus on this before I arrive.
No need to speak arabic but try and learn when you come

2. What is the social attitude about alcohol consumption?
No problems, plenty of bars, clubs etc about however it doesn't do to be out in the street roaring drunk

3. Will it matter that my partner and I are not married? (socially, not visa wise)
No, people around you will not know if you are married or not, unless of course you tell them.
You would only have a problem if the man in question was Egyptian

4. How safe is it?
Relatively safe but petty theft is on the increase, but saying that you are not going to be shot, knifed etc

5. Are there any social clubs for expats?
Lots of clubs for expats

6. What are local attitudes about dogs? I have one that will come with us.
Egyptians dont like dogs, muslims consider them unclean but there are dogs around.
Where are you going to stay? There are no public areas that I know of, where you could walk your dog, other than out in the desert. If you go to a park you certainly could not let him off his lead.

7. What is the availability of international foods?
You can get most things here in Cairo

Any help anyone has would be great. Thanks!