Some guidance...

Welcome to the forum travelbug4

I hope that other members will bring their contributions to your several queries soon.

Regards

1 & 2: 45,000kr is more than enough for one person. The tax rate raises depending on how much you earn. I think for your salary it will be around 36%.

3: You will be able to hire a 1 room apartment for 5,000kr. In that price range I imagine you'll get between 35 - 45m2. The best places to look are property websites like boligbasen.dk and boligportal.dk. They charge a fee for a few month's registration, though.

4: I am not too sure about that. Ask them if they can assist you getting registered in Denmark to get your CPR number, etc. The bureaucrats at the immigration centres can be amazingly difficult to deal with and it can end up leading you on a wild goose chase. Also, a lot of landlords are a bit funny about letting an apartment to someone without a CPR number. So maybe you can ask your employer to help you find a place to live. 

5: The state provides free language lessons for up to 3 years in many language schools across CPH. I started the lessons about 2 weeks ago and they seem OK. There is a waiting time of around 1 month from the interview date to when the lessons start. Of course you can pay for private and more intensive lessons.

6: Alcohol, restaurants and public transport.

7: Depends on your standards. If you shop in the cheaper supermarkets like Netto and Fakta you can get away with spending around 2,000kr for yourself. I personally mix the cheaper and better quality supermarkets and for two people we spend around 4,000kr per month.