I love EQ and I don't think there's any other program like it, although there are other programs that approach it differently.
Here are your answers:
1. You can design literally anything and you are not restricted to blocks. You can use any type of setting including a variable setting, where you place your blocks or whatever shape pieces precisely on the quilt. If you want me to send you an example of what I mean, let me know. That said, it's smart to start out designing with blocks and then moving on to more challenging settings.
2. The finished quilt sizes are not set; quilts can be virtually any size. I generally don't start out with a size, but build my quilt and adjust block size and borders to the size I want.
3. It has a layer for blocks, one for applique and one for your quilting design. I have not used the quilting designs much, but I know there are a significant number built in to the program.
The program comes with libraries for blocks, fabrics, applique, quilt designs, etc., all of which can be easily added to.
I'm a fan and think it will be excellent for your purposes. It works really well for my original designs.
Hope this helps - feel free to PM me with other questions.
LJ