Pressing the quilt top at the end is always a good idea. If you try and press the seams open now, the intersections may be even bumpier :wink:
Ripping the fabric is easier than cutting long pieces... I make the cut 1/2" wider so that I can trim both edges, they will be a little frayed from ripping them.
If you are not cutting the borders from long yardage, you may consider just cutting it too. It is really a personal preference :D:D:D