"It is also best to get in the car and only press overtake when he is in the best position to overtake."
This is an interesting point, and something that I'll certainly try. B Spec knowledge seems to be scattered all over this forum, maybe there should be a specific B Spec thread to pull it all together?
Regarding your point about increasing B-Spec skill levels for a specific track, I don't get the impression that B-Spec works in this way (although if anyone has definitive knowledge to the contrary I'll bow to their wisdom). I've been trying to boost my B-Spec rating for the past couple of weeks as I want a competent co-driver for the endurance races. My impressions of B-spec'ing are basically as follows,
1. B Spec skill levels grow fastest when the B-Spec driver gets new experiences, ie new cars and new tracks, in other words the B-Spec driver has a voracious appetite for novelty.
2. The opposite is also true, if you keep B-Spec'ing one particular race with one particular car then you get fewer and fewer B-Spec points, for example I B-Spec'ed the German Touring Car series in the European Hall with the same Opel Astra regularly in order to raise money, now I don't receive any B Spec points from the exercise.
3. B Spec points also seem to get a big boost from the specific race where the B Spec driver actually wins the series or championship. For example, in the Nissan Silvia series I got about four or five B Spec points for just entering the first race without even winning it, as the series progressed there were few or no additional points for winning each of the races, until the last one when about thirty B Spec points were awarded along with the prize car. So if you want to accumulate B Spec points don't ask the B Spec driver to do the leg work and then step in for the final race to grab the glory!
4. B Spec skill seems to be transferable, in other words if you've got a a lot of B Spec points your driver will be reasonably competent even in a car or on a track that he's never seen before.
5. And the opposite seems true, when I first started to accumulate B Spec points my driver didn't seem to be perform noticeably better on the few tracks or cars he was familiar with. Furthermore, I've been B Spec'ing the Opel Speedster on Suzuka East and Infineon multiple times in an attempt to win (as well as testing settings in the family cup on these tracks), and I'm no longer getting any additional B Spec points and my B Spec driver's times aren't improving. So, even though it goes against real life experience, pushing the same car around the same track in B Spec mode doesn't seem to significantly improve B Spec skills in that particular car or on that particular track.