My wife and I recently got our first Brittany (Piper

1. Potty training - she's doing much better. We have maybe 2 or 3 accidents a day, but that's mostly on us (waiting a bit too long to get her outside). She only pees inside, has never gone #2 indoors. She holds it well in her crate (2-3 hours easily), but seems to go every 10-15 minutes when she's roaming the house. We try to take her out every 5-10 minutes after she drinks for about 4 or 5 potty breaks, but still have a few oopsies. She doesn't give many clues that she needs to go. Kinda stops playing and then pees 5 seconds later. Is this something that will just take time and repetition to learn that indoor potting isn't good? Are we doing anything wrong?
2. Play biting - I've read enough to know that her "zombie biting" fits are perfectly normal, but not too many posts about correcting it. We've tried distracting with toys, but our hands, jeans, and shoes are more interesting to her. We've tried dominant behavior with gentle muzzle holding, reprimanding, etc. That only seems to get her more wound up. Seems like the best approach is a timeout. Sometimes it works, but often times she goes right back to it a few minutes later. She walks usually 3 times a day for 30 minutes, plays fetch, runs around, and gets plenty of exercise. Not sure what else to do.
3. Digging - saw another post about this, so I assume the random digging is normal? She does it in the yard, on the tile, along the molding, etc. Just something she's prone to do?
4. Defensive behavior - this just started within the last day or two, but it's the biggest concern I have. Once it was a stick and the other time it was a bottle cap. We went to pull it out of her mouth for fear of her choking on it, but she bit pretty hard. Not a typical puppy bite, this was pretty obviously aggressive. She's never done anything like that before so I want to nip it in the bud early. What is the best way to get her to leave things she places a "high value" on without simply removing it by force? She's great with drop it when it comes to most items, but not with these random things (caps, cig butts, wrappers, etc). We've been very clear that we don't want to use a heavy hand with her, so I don't know how to show that we're the alphas of the pack without doing something aggressive in return.
5. Stinky ear wax - Pee-yew! Does my dog produce some fowl ear wax. The vet checked her for mites and it came back negative. I've been using cue-tips to wipe out the wax, but I'm not comfortable enough to get deep (she's too fidgety to get in there). Comes out almost black and smells like rotten cheese. The routine cleaning has helped the smell, but she still produces a lot. This is my first "floppy ear" dog, so I assume it's just a normal problem. Anyone else had to deal with this?
6. Socialization - we didn't let her around many dogs until she got her 11-week shots. She would meet dogs, but didn't play with many. Now that we're socializing her routinely, she's often times too much for the other dogs to deal with. She plays like a typical puppy: chasing, jumping, nipping occasionally, but the other dogs seem intimidated by her. Most dogs are her size, so we introduced her to a friend's extremely well behaved 12-month old Husky mix and she was a wreck. Scared to play with the other dog despite the husky's very playful intentions. She was squealing and barking at the dog. It goes without saying, but the play session only lasted a few minutes. She was very interested in the dog, but not really "playful". If she's too crazy for small dogs and too timid with larger (50ish pound) dogs, what do we do to get her to be comfortable?
I realize some of these questions probably sound silly or amateur many of you, but I figured this would be the best forum for learning more about our poochie and her tendencies. Any feedback you can provide would be greatly appreciated!
Also, not sure how to post a picture, but if someone can tell me that too I'd love to share a photo of her!
Thanks in advance,
Logan