VS2005 validator <> W3c validator ?

[teo]

hallo

I'm using vs2005
I set the validator to 'Xhtml transitional 1.0'
I notice that the validator fails
It doesn't detect some errors and it considers other ones as error
but they are not

I'm ASSUMING that what w3c validator says is RIGHT

- - - - - - - - - -

in example :

vs2005 validator says nothing about id="5hallo"
and
w3c says the digit 5 at the beginning is not allowed

also

vs2005 says align="justify" is not allowed
and
w3c accepts it

also

vs2005 says nothing about the char < in the text
and
w3c says I have to use the symbolic equivalent

- - - - - - - - - -

Is the vs2005 validator wrong?

Is it possible to fine tune its rules?

If I have to manually edit some schema file,
I ask you if you have a schema file perfectly acting as the w3c acts
so I can download and replace the current vs2005 schema file

- - - - - - - - - -

Another thing (partially related)
on creating an aspx page, the Viewstate field is called id="__
but the w3c says that __ is not acceptable

How is it possible?
How to have the aspx page 'Xhtml 10 transitional' valid since its creation?