Technically you don’t need a PPL to get a CPL/IR or a MPL… If age isn’t in your side (30+) i’d advise you budget well & do it as quick as you can, careful when & how you climb the ladder…
Yup, if you’re enrolled on an integrated course you don’t need the PPL! Otherwise it’s a necessity, partly 'cos you need X amount of P1 time before beginning the course, plus the night qualification.
And what I meant was, you cannot get an ATPL unless you’ve held a multi crew commercial job for a while, or have access to your own multi crew aircraft and pay for it, and the other pilot
This is because you need so many hours multi crew experience (think it is/was 200 or 300) to qualify for a full ATPL.
What you mean is the ‘frozen ATPL’, which is basically the CPL/IR/ATPL exams. Not an officially recognised term though!
I would advise against becoming an airline pilot. I flew for XL airways until 2008 when they went bust, not flown a heavy jet since… It was about 10-15 years ago that the job started declining. Most people have the skills to actually become a pilot, it’s not ridiculously difficult. It IS ridiculously expensive and when I was training, there were two types of people alongside me. Rich 18-20 year olds (mummy and daddy paid) and 30-50 year olds who’d saved up the cash and will probably never have enough time before retirement to become a captain.
I’m not a doomsayer and used to despise those types, but really, it’s not what it used to be which is a shame as it’s a wonderful dream to have. Airlines are run by beancounters these days, not ex old school pilots who moved to flying a desk and knew how the game worked.
If you want to fly, I think the best way to go now is accept that it will rule your life, and get around the world doing bush flying/aerial photography or similar. You probably won’t make mega money, but if you want to fly that badly, at least you won’t be depressed when you’re sat in your armchair aged 80 
Anyway, sorry for the thread drift!