Is Smokey's way of rough playing with the puppy appropriate and okay to let her do so?
Tsunami seems to like her as a chew toy and he's only once yelped when she pinned him down...

Since Tsunami is giving as well as he's taking *I* see nothing wrong there. Smoky isn't holding Tsunami down against his will and Tsunami actually goes after Smokey a couple of times; it looks like they understand just how much and how hard to grab.
They look like two very well socialized dogs who are quite comfortable playing with each other.  
Now, that said, I'd still keep an eye on them until he gets a bit more Smokey's size just to make sure he doesn't get accidentally hurt.  The way they're playing now, I see a real disaster (of a good kind) in the making when they get older.  You might want to start working on "okay, enough" (or similar) so that you have verbal control over the play and can stop it when they go through a wall.

Normal husky behavior! The yelping can actually be a good thing, as long as the other dog backs off when they hear the yelp. They have to learn to communicate with each other.

Normal! Watch for the behavior after the yelp. If the yelp happens and then play resumes you are good they are communicating that is all. If the yelps happens and one dives in threatening or runs away (Or tries either) watch to make sure that you do not have to call it quits because one is not "listening" to the other.

Hopefully they don't go tyrough the brick walls! Lol
I see your point there, Smokey already knows "finished/enough" so she listens when I say enough is enough, but then Tsunami will start it again... He seems to be a rough little guy! I'm amazed at how good he is with other dogs and he does not nip at all! I see now why everyone says that Huskies should stay longer with their parents/sibs...he was 9 weeks when I got him and it makes a world of difference from getting Smokey at 7 weeks!
I keep him on a leash when outside with both Smokey & Brolloks, since B is a mad pup and will run his legs from under him, or run straight through him!
Hoping he will get bigger size soon so he can play with them more! He is quite a huge puppy according to my vet, weighing 8kg when I took him on 9 weeks! He's a lot bulkier than Smokey too, she's so skinny you can see her ribs when she goes on a hunger strike!

They continue straight through the yelp...Smokey just let go of his neck/shoulder and they get straight into each other again...I have to say he prefers Smokey over any chew toy and he bites the crap out of her! He knows just where the soft spots are to get her off of him!
But it's good for her to have fun again, after Wollie died she cried the whole time and wouldn't do anything or eat :-( now she has a little furball friend again!

We recently added a 6 month old to our pack. Him and our 3 year old play non stop. I have a saying now, who needs chew toys when you have a brother? lol

True! And they get loads of exercise playing like that, it gets Tsunami tired very quickly!

Bourbon my 3 yo sibe finds his 8 year old Australian Shepherd sister to be the BEST chew toy still to this day!

I will echo the above posts - when son got Archer, he and Ami became fast wrestling buddies and are to this day. Unless it is really hot out, you will find them either rolling around on the ground with Ami's neck in Archer's mouth and Archer's leg in Ami's mouth or running at full tilt with Ami's tail in Archer's mouth. Whatever, Archer always seems to have a mouthful of Ami's tail.

I found it very disconcerting at first but now i'm used to 2 "wolves" duking it out on the lawn

Oh yes, Smokey's tail is a favourite by far!!! He loves chasing it and to finally sink those little razor sharp puppy teeth into it!!!