Tony,
Congrats on the new puppy!
Please remember to sign your posts so we can address you by name. With 900 and some members, that is quite a daunting task to remember everone by their 1st name until you have posted more frequently.
Sleeping through the night: that may take some time. When he gets up let him out to go potty and put him right back to sleep. Be sure to take him out a few times before bed as well - just to be sure he has gone completely.
I 'd say 14 weeks and he should have it down.
That may vary of course.
Do not have your kids run in front of the dogs on a walk. That is likely why he things chasing them off lead is also okay. He likely has good intentions, but it is not a good habbit to create as the norm.
Never encourage your pup to do what you would not want a 90 lb dog to do. Chasing kids is one of those things. Do not have them play wrestle or tug of war either.
Can they hide behind a tree and call the pup to enforce recall and make a fun game out of hide and seek at the park?
Puppies often lag behind. just talk sweet and encourage him along Maybe even bring some treats with you to provide extra encouragement to walk nice.....and do not encourage pulling you. That will back fire when he gets bigger

They are not all dominant dogs, but they do need a firm hand and positive reinforcement.
Cesar Milan's is not a bad book to read. If you look in the library thread, you may find some other suggestions.
At 4 months (once vaccines are complete) you can take him to a beginner training class & I would follow up with a 2nd session too
Work on basic comands with treats for 5 minute increments every day 2 times a day and have the kids treat him for sitting or coming when called too! He will begin to respect them as minature leaders as well.
If he is mouthy (normal for a pup) have the kids remove their hands from him when he mouths. "Gently" hold his muzzle and tell him no mouth or no bite. You can get a spray like bitter apple to put on the kids hands as well that will cause him to associate the kids hands with a yucky taste that will discourage him putting his mouth on their or your skin.
Grass, well - better than the flowers! He is exploring his environment with the best tool he has, his mouth. too much grass can cause a bit of an upset tummy - but nothing fatal.
Bring other toys in the yard to give him to chew on out side and distract him with those when he goes for the grass.
Hope this helps and others also give some input on what has worked for them too!
Melissa