Noggin,
Just to pick you up on a few points
"Yes it is possible to do a PPL in 21 days but not to be recommended" Why?
"Ideally about 6 weeks is the optimum time for absorbing all the necessary material" Based on what information?
"Schools that offer a 45 hours PPL in 21 days provide you with exactly that, a 21 day PPL; there is no guarantee you will be any good or anything better than just about safe enough to get a licence" Where did you get that little pearl of wisdom from?
"if you then wait several months before you fly again you'l probably need another 15 20 hours to convince a school to let you hire their aeroplanes" What the f**k? I waited 6 months between passing my GFT and taking my checkride at Newcastle - I was signed off after 40 mins.