Volkswagen Golf steering locking and cutting engine out!!?

Hi, I've been experiencing a number of issues which appear to be linked somehow, since I had a new battery last month. The steering wheel is locking, especially when turning into roundabouts which in turn cuts the engine out. It went for diagnostic tests last week and I was told it was the throttle valve body assemble that would eventually need replacing but for now,they re-set it, saying that this hadn't been done after the battery was replaced. Today the break has been pumping like there's no resistance behind it and making a similar noise to a bike pump, although it appears to be working, steering is locking and cutting engine off again, and when i turn the ignition on, it's revving to 2000 without touching the pedals??? When the engine cuts out, the cd player goes off and when it comes back on the volume won't go up as if a speakers blown, any ideas and is it safe to drive back to derby from manchester to the garage it's just been to??? Cheers.