UK Driving License Exchange & Buying a used car (Frankfurt)

Hi there

I had a few questions regarding exchanging my UK driving license to a German Driving License

1. Is it mandatory to exchange the full UK driving license from UK to EU or German Driving license?
2. Do I need to give any tests again? I got my Full UK Driving License, exactly a years back.
3. Will it be a exchange and I need to submit my UK driving license? or will it be an additional license granted to me on basis of my UK driving license (I am looking for an option, where I don't have to spend too much on training or driving classes)
4. I will be working between my London office and living and studying in Germany. Is there an option where I can hold both the licenses for each country.
5. Buying a new car and insurance on a 1 year old full UK driving license or a newly exchange German driving license. Which would be better and economical. I am looking for a decent second hand, either basic hatch back or saloon car. Do not mind right hand or left hand. As it will be driven equally in London and across Germany.

Many thanks for your help and suggestions in advance.

Regards

KJ