The Probs are as follows.
1, Clutch pedal not lifting, could this be the master cylinder seal?
2, Hill holder unavailable/vehicle protection system unavailable, clutch microswitch?
3, rough idle when warm, injectors?
4, this morning when starting her from cold, there was a horrendous noise from the engine, like a squealing coming from a belt. on driving home she was back to normal .
5, reluctant to start from cold, glow plugs?
Clutch pedal could be master cylinder seal or it could just be the actual pedal mechanism, they can be "sticky".
Hill holder unavailable could be clutch or brake microswitch but after seeing point 1 I'd say it's related to the clutch pedal not lifting correctly.
As for the rough idle, try putting a bottle of injector cleaner in your tank but don't follow the instructions
add it when you've got less than a quarter of a tank left.
The squeal is probably a worn or not tight enough accesory belt, nothing too sinister.
Starting reluctance, wait a little bit longer between inserting the key and pressing the button (I wait till it says "press brake or clutch to start"), that gives the fuel system time to reach pressure. If it is glow plugs though, they're a cheap enough fix.
Then when you've got that lot fixed, take it to Gus at Alfatune and get him to make it the car it should always have been
(can I get my commision now Gus?) Actually I think there's an Alfa specialist in York that does the Alfatune/AHM map.