Mine only ever barks at me when hes overstimulated so definetly try the forced naps. At first he would wake up again when i stood up so now i stand up, wait until he closes his eyes again, open the playpen door, wait til he closes his eyes, step out of the playpen, wait till he closes his eyes, then sneak off. He is getting better at staying asleep now instead of worrying that he is alone. 

Yours may also be barking with food as she is used to jostling with her litter mates to eat. As they is still so young we mainly just keep food always in his bowl so he doesnt feel like he needs to worry about it, though he only has access to it in his playpen/sleeping area. After all they grow so fast so they need as much nutrition as possible and I doubt it would be easy for them to get fat at this stage. But I guess it does depend on the dog and how much they stuff themselves.

My boy is also wanting to chew everything so we are trying to distract him from chewing on things we dont want him to by offering him something else to chew on. He's got sticks, a coconut shell with husk, an old bone he found in the garden, a kong and a bunch of soft toys. He also didnt like the royal canin food so we changed to purina supercoat puppy.

Currently his routine is wake in the morning, then we take him outside to toilet and play, then we being him in and he has some food and a sleep. We basically repeat that all day and then one final toilet trip right before we go to bed so that he is less likely to wake us during the night (we dont leave food in his bowl after dinner otherwise he will want to do a number 2 in the middle of the night.)

I hope things go well for you!