You have a fabulous quilt for a newbie!
Yes, when you go around an applique, that's echo quilting. You can echo as many times as you want.
If you're pretty sure about the batting info (2 to 4) then I would make the assumption that 4" would make the quilt secure enough. Again, this means that you need to have a line of quilting no more than 4" apart in any direction. So take a tape measure and measure from your echo quilting to the sitd around the squares. If it's 4" or less, then that area is OK.
but it has to be 4" in ALL directions, so from the cup handle to the edge of the block might be ok (horizontal) but if you measure vertically, next to the cup, you have 10" or so with no quilting, which is not. So you need something across this area to secure it.
I would make a paper mock up of a block. Sketch the cup and steam echo stitching. Use a sharpie for this, then doodle a bit with a pencil and measure to see what the unstitched areas are. Erase and try a different idea. Your additional lines are good, and I would also try connecting the mid point of each side and connect them. that will give you a diamond, then maybe echo this.
I would do a heart inside the cups.
Last edited by PaperPrincess; 12-14-2012 at 03:50 PM.