The "trainees sitting around doing nothing" comment is concerning. I'm currently on hold and if I do get offered a job I'll be taking a hefty pay cut while I'm in training* so the less time that takes the better. To have that time prolonged due to having many days when you're doing nothing doesn't sound good.
* - I don't actually know what the training pay is tbh with you but whatever it is I'm resigned to accepting it for the long term increase once qualified.
Anyway, kind of jumping the gun a little, not even had a medical yet.
Training rate currently £24,793 + time and a quarter for any Sundays you do during handling stage.
I don't know of any trainees 'doing nothing', although it is true that some are doubled up to a DI.
Recent pass out times have been approx 13-14 months from start date, but this will vary depending on your depot and which routes your DI signs.