A few good points - Non technical skills is a new thing within the rail industry for drivers that has directly come from the aviation sector mainly from pilots. NTS is to be fair a huge workload for DM's and in my opinion drivers of trains have been using NTS for years. As for 40mph past a single yellow, signal spacing is mainly down to line speed, gradients and sighting so if the line speed is 100 or 50, 40mph passing a single yellow should in fact be a safe measure however it is a drivers discretion on what speed they pass a single yellow. A few points below on my opinion of the importance of a drivers role on caution signals.
1. Continuous approaching or 2 yellows - train in front, know what the train is, where it stops and regulate your speed so you see greens and not a preliminary caution.
2. Know you routes well enough to know the gradients and location of the train in front.
3. Treat all track approach signals as normal red aspects to be doing only 15mph 200m from the red.
4. Adhere to the PDP by using no more than 50% power on all occasions when under cautionary aspects.
5. Know your traction and the prevailing weather conditions.
6. Never presume anything always treat a stop signal as a stop signal, the train in front may have stopped out of course.
As for chasing yellows being a "frequent reason for SPAD's" where is your evidence? I feel that this is an in-frequent reason. The most frequent reason being a SOYSPAD or a SASSPAD and this is where the NTC will be a huge help.
The workload is high in respect of NTS because it is a new system and takes some getting used to. Recently in my company, DMs have had to duplicate ride outs and download reports, one in the old style and one in the new NTS style. This clearly will not go on forever! NTS is also having to be explained to a bunch of cynical drivers which isn't easy but eventually it will become the norm and people will adapt. It is certainly here to stay so as people get used to it, things will become easier.
I actually feel that it has not been explained well to drivers (possibly because those doing the explaining don't fully understand it themselves,) which is unfortunate because giving people a better understanding of Situational Awareness, Workload Management and Conscientiousness, to name but three, will hopefully result in fewer SOLs.
For incident investigation as well NTS is going to be useful. Why did the driver have a lapse? Did they prioritise the red signal over the station stop correctly? Are they reading their notices and keeping up to date with rules? But I am digressing from the point.
I disagree with your point 4 by the way, "
Always adhere to the PDP by using no more than 50% power on all occasions when under cautionary aspects."
a) because, thankfully, my company doesn't have such a restrictive PDP, they let us get on with it, and b) because often it is unnecessary. If you leave a station on YY and the next station is before the Red, what is the point of taking half power? You will only lose time. Sometimes on metro routes you can even leave on a single Yellow and the next station will be before the red. No point taking half power then either, open it up then straight onto the DRA when shutting off.
As for chasing yellows being a frequent cause of SPADs, well I guess it depends on how you define frequent! I can think of at least 3 within the past year which were caused by repeated AWS cancelling although a couple had TSRs involved so not just chasing yellows. SASSPADS are rare now, in fact I don't think we had one caused by that last year. SOYSPADs are more common but by far the biggest cause at the moment seems to be shunting SPADs and poor use of the DRA and checking procedures (NTS again!) when changing ends.
With route/diagramming knowledge there are stations I can approach while coasting with the signals dropping off to less restrictive aspects as I approach them, for me to roll smoothly into the platform on time 
