Cedar

I have finished piecing my first ispy baby quilt top for a little girl arriving at the end of the month. This will be the first quilted quilt I've completed (I've quilted potholders and birthed a lap quilt) and at this point I have a bunch of decision making stuff and questions that I figured an outside perspective could help with.

Obviously there's a couple of squares that still need trimmed. I also have a couple of places where the fabric is puckering. This was my first time doing different sized squares and I ended up sewing in a strange order in some places. Is there a good way to fix this?

Border -- do I need one? I know there are lots of great quilts without borders, but if it will look better with a border than I should have one. The dimensions are 33" x 49" I'm also wondering if a border will be mechanically useful -- since binding is still pretty new to me would having something between the blocks and the binding make it more forgiving of mistakes?

Backing -- I have a 43" x 26" piece of fabric that I want to use on the backing. It's not a panel, but it has a nicely flowing repeat that my boyfriend insists shouldn't be cut. Obviously I'll need to add fabric to this. Originally I'd thought I would just add borders, but now I'm not sure. I'm remembering making the back bigger than the front for shifting room and I'm thinking of a lot of ways shifting could be horrible with a centered panel. Is there a trick to this?