[Seaside] seside 2.5a questions

[ld]

I'm learning seaside, starting with Version 2.5a.  It seems the best way 
to learn is to ask questions, so here goes:

1) WACounter initialization.  What does
       registerObjectForBacktracking: self.
actually do?

2) When would I use:
         # registerAsApplication    method?
Should it be  used for embedded components? or for only those where 
#canBeRoot is true?

3)  WACounter.  Does #children need to be defined as follows?
       children
          ^ counter

4) WACounter:   if I add a #step variable to hold the rate of  change, 
would #childern become:
       children
          ^  #('counter' 'step')

Thanks for you patience.

-Larry Kelly