Scratch

I have been thinking a bit about using Scratch as a math environment for algebra and pre-algebra classes.  I have used Scratch to build some basic apps, but I an trying to anticipate issues down the road.

1.  Can I "import" or "merge" a scratch program to an existing scratch program.  For example, could I post a program for students to incorporate into a Scratch program of their own.  I am thinking that they could add my program to their program and not simply use mine as a template before they start.

2.  Can I visually animate items to move from one section of the screen to another?  For example, let's say I build a program to multiply two numbers (from 2 text boxes) and place the the result into a third text box.  How easy would it be for me to take the answer from the "result" text box and feed it to some other text box as part of another calculation.  I think about this when students might use Scratch to solve an expression using multiple steps and respecting the order of operations.

Thanks in advance for any thoughts,
JDF