I think size 17 looks good on you (you have a very pretty arm btw

). I have size 16 and the fit looks the same on me. I could turn the bracelet around my arm if I wanted to (to even out the scratches), which is great because you don't have to unscrew and re-screw the bracelet yourself and risk doing it incorrectly and having the bracelet fall off. But if you think you will enjoy size 16 more then you should be able to exchange it at the boutique.
Also, I read that the cleaning kit and travel pouch are supposed to be given after servicing, but some SAs include them with first time purchases to improve the experience for their customers, which is why you didn't receive it with your online order. But again, you should be able to ask for them at the boutique.
As for whether you should wait to receive the bracelet from your DH, I think the bracelet from your mom represents a different kind of love? Maybe it's because I received mine from my parents after a successful internship, but I think your love bracelet will have a special meaning whether it comes from your mom or your DH. And this forum has endless suggestions if you're in search of an anniversary present

!