Although Wainrights is an ok food, it does sound as though it's not the right one for your puppy, that many poo's ( if there's no underlying problem ) would suggest to me that his food is traveling through his digestion at a rate that it's not being fully utilised, resulting in a lot of waste.
Are his poo's very smelly, soft of greasy ?.
It could also be that he's getting too much at meal times, which could account for him not eating his last meal until four hours after it's been offered, and also be a very simple reason for all the poop.
Training wise, I'd ditch the puppy pads, it just slows things down, and if you have some holiday time, set your alarm to get up half way through the night to let him out, I'm sure you will crack the house training eventually, some breeds can be a bit slow.
Good luck

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