he has SEVERAL toys of all differents types and yet still finds a pencil or underwear or chair to chew on…
Manage his environment better. If he's getting pencils, etc, it is because you left them within reach. Of course he's interested! He's only been alive 16 weeks. THE WORLD is interesting!! Just take the offending item gently (I always thank my dog for finding such neat things!) and offer him a "legal" toy instead. Praise, praise, praise!
the only time he is sweet is when he is tired meaning he also chews on ME.
Hooray! You want him to chew on you! You have 2 weeks left to develop his ABI (acquired bite inhibition - how hard he bites when he bites). After 18wks of age, ABI is "set" for the most part. A dog MUST be allowed to bite humans if it is supposed to learn to do so gently and about 9 out of 10 dogs will, at some point, put it's teeth on a human for some reason. Knowing how to do so using minimal jaw force is a learned skill. If your puppy's bite hurts, YELP and get up and leave for 15 seconds. When you come back, if he doesn't bite more softly, YELP and end the play session. Over the next two weeks expect softer and softer bites.
Once our puppy is 18wks old, that is the time to start teaching him, you know, really, you shouldn't bite. If he puts his mouth on you or your clothes just tell him (in a normal tone), "Too bad" and leave the area. Play time is over. Too bad, so sad.
Also i am crate training him. At night… no problem sleeps well through the night, no noise or yodel or howl. but during work hours i have to crate him up too 6 hours.. [snip] but when i get home he has peed more then once in his crate and then shreds his sheet.
That is too much crate time for a 16wk old puppy. Average ability to "hold it" is 15min per week of age. That means your puppy should not be crated (during the day, night is different) more than 4hrs. You need to have a long term confinement area that includes a puppy toilet.
See Before You Get Your Puppy for more info.
Get into Puppy PreSchool right away with a qualified trainer ASAP. This is all normal puppy stuff.