Welcome to the club. The 2.0 is the same engine as you had in the pug, just an updated version.
The aircon will probably be the condenser, I've read its a common problem and I've had to change mine this week because of a tiny hole in the passenger side of it, diagnosed with some uv dye.
The economy might not be as good as the pug as its a heavier car. I'm averaging 45mpg working it out brim to brim and that's mostly on the school run, but can happily get 65mpg on long runs. What are you getting?
2004 Magnum Grey 2.0 TDCI Ghia