Yes, yes, and yes
. The only things I would consider are:
1. Fading and shrink may differ from the 100% cottons, so that may influence your quilt design.
2. Sew a few test samples side by side with any 100% cottons you'll be using. Occasionally I get some poplin that is sooooooo tightly woven I need to use a different needle and tension setting to avoid puckers. Not likely to be true of scrub fabric but I would still test before use.
The blended scrub poplins that I have are mostly quite soft, nice drape, virtually indistinguishable from 100% cotton. I have to look at the label to know which is which.