
I think in general, you are on the right track. The one thing I would suggest is, at this very early stage, you don't wait for him to ask yet - YOU dictate the going out. As for bells - dogs aren't stupid and all too often, realising that ringing the bells, if you can get him to do that at all, means you come to let him out.... so he wants to be outside = he rings the bell. Not because he has a need to pee, necessarily.
Going out more than once overnight (which you will need to be doing once, by around 3 am) - are you upping the heating a bit overnight. If the puppy is warm and snug, he should be sleeping through. If he starts feeling chilly, he will be restless, and once awake, need to be peeing at least. If he goes to bed by around 11 pm he should be able to go to around 3 am before needing out. Try to anticipate his need so he doesn't get the message he stirs, you come. And that will also give you time to put your coat on so you can go with him out there to see what he does.
Mine have never had water throughout the night BUT they do until they go to bed, and again first thing. Never has any gone straight to the water, so I don't believe they need it overnight - when they should be sleeping.
Rule of thumb. Correct only in the act so the pup knows what you want and don't want. Loads of praise when he empties outside. If he doesn't when you take him out and you know he must need to (timing), bring him in but don't let him have the run of the house. Keep him by the outside door, stay with him and the moment he goes to squat, say (don't shout or he may run) NO! and take him back outside. You may need to be repeating this to prevent him coming back in and peeing. Clean where he has his mistakes so he doesn't go there again. You might keep some thick towels to hand to soak up any mistakes before it gets into the carpet.
Feed his last meal before 5pm to give it a chance to be digested before bed. If he has a BM soon after a meal, that will be what he had before ... digestion in the healthy dog usually takes around 4 hours.
Ignore what his siblings are able to do - each pup is different. Be persistent, patient and consistent. Housetraining will happen, but probably not totally until around 4 months unless you are very lucky!!