I think they are more likely to take people with no experience. It's easier to teach from fresh than to remould somebody's bad habbits
Mmmmm, not sure about this.
When you say "bad habits", a qualified driver is unlikely to have many as he probably wouldn't still be driving, or his safety record would be such that he would be discounted from selection.
TOC's have a history of employing people from jobs such as police, fire service, armed forces, prison service, all of which have some of the disciplines required by drivers. Or employing from within - guards, revenue staff, platform staff, depot drivers etc. It would be naive to think that internal recruits are free from "bad habits" but their experience of working in the railway safety critical environment makes them a lesser risk than a recruit fresh off the street.
Whether Virgin will stray far from recent TOC recruitment norms is open to debate. On one hand it's a stagecoach operation, but on the other hand expect a few left-field hires which will gain Virgin some nice PR spin.