Use of modal verbs

1841.1

Hey, folks...which would you choose to say and why?

I must hurry if I am to finish these few, final lines.

I have to hurry if I am to finish these few, final lines.

I'm sure nobody is reading this thread anymore, but I must correct myself if I am to sleep at all tonight!
I'm sure nobody is reading this thread anymore, but I have to correct myself if I am to sleep at all tonight.

I have to decide if I am to move here, and the thought of change has made me jittery.
I must decide if I am to move here, and the thought of change has made me jittery.

There are still two more big ingredients left that I have to mention if I am to catch the full flavour of the 1950's Bop.
There are still two more big ingredients left that I must mention if I am to catch the full flavour of the 1950's Bop.

I have to understand how people learn if I am to be a facilitator of learning.
I must understand how people learn if I am to be a facilitator of learning.

Now, I must decide if I am to sign my life up to the state by June.
Now, I have to decide if I am to sign my life up to the state by June.

Thanks.

Is this homework, position?