I think the IMC training is going to be a lot easier if the pilot has say 20-30 hrs minimum ON TYPE, solo on decent cross-country flights, before starting the training.
Re Trevor Thom Book 5, I think this is not a good book! It reads as if different bits were written by different people; it's quite disjointed, and some of the diagrams in my copy did not make sense to me or to anyone else (probably errors).
The best single thing is to find an instructor who actually flies to places, IFR. VERY few of them about! I would stay well away from those instructors who just have a very old IMC Rating and have rarely been past the folds in their chart. They can teach the bare syllabus OK, and will spend £1000s of your money doing NDB holds for hour after hour to perfection while you sweat, but the end result will be of little use to someone actually wanting to use it (one could make a similar comment about a PPL taught by instructors who never go anywhere...)
Yes, there are many expired IMCR pilots about. I suspect this is because most of them never realised they will need to maintain current, and get a suitable plane. Most school planes are not suitable for real IFR flight; a lot of the avionics don't work properly even if they appear to work.