doubts on Upgrade Tools from upgradejde.com

 Hi, 

I have read documents about two utilities  in upgradejde.com site.

Customization Object Analyzer and Application Configuration Analyzer

I have also read support documents about those utilities but still have some basic doubts.

In my case I wanna use those utilities to prepare my Upgrade from XE to 9.1 

So , some questions :

1.  I understand that I must run those utilities in my current environment ( XE ) , right ?

2. Should I run on my Production Environment or on my Pristine Environment ?

3. Should I update my Pristime Environment if is the case that if is outdated ? ( more than 6 months ) 

Thanks in advance for your help.