So I started writing a waltz. I have been mainly focusing on the bass line because I got advice from someone that if I focus on the bass progression, the basic melody will just come to me. And once I have that basic melody, I can embellish it however many times I want until I get a pretty melody that isn't boring. And I have made 2 images of the same section, one to highlight the different parts and the other to make the notes easier to see.
Here are the notes:
As you can see, I end with a first inversion tonic chord which still has tonic function but is less stable.
And here is the one with the colors highlighting the structure:
Highlighted in red is the first phrase which ends with a half cadence(which I think is at the dominant triad instead of the seventh chord and that the seventh chord is just to transition to the second phrase). Highlighted in blue is the second phrase. And highlighted in green is the authentic cadence at the end of the second phrase.
This is an imperfect authentic cadence because while the dominant triad is a regular cadential dominant, the tonic triad after it is in first inversion. I wasn't wanting too much finality but I wasn't sure that I wanted to extend the structure either, using a half cadence. The IAC is like the middle ground between an HC which gives a sense more music is coming and a PAC which gives a sense of total finality.
So I was wondering, is it okay to end my period with an IAC like I did or should I do a leap to root position and end with a PAC?