As i said, everyones circumstances are different. My previos post was just an example of what is possible. It is possible to do modular quicker than integrated and people have. If i were in your position though i would just get the PPL then get a share and just fly as much as possible whilst doing the ATPL's. By the time you have this you will know how the industry is looking. If its picking up then go straight into the IR.
When it does pick up it is not going to happen overnight. There will be lots of experienced pilots from failed airlines before you in the queue. When these start getting picked up in large numbers you know its time to get the IR.
As to how many hours per week, its as many as you can afford. the 100 hours is just a minimum. Any over this is a bonus and will add to your TT. If you get an ME then even better. Just make every hour count by trying to improve your flying each time and setting goals. Try not to pick up bad habits etc.