Stop Tidy replacing unexpected tags and warn on upper-case tags

Hi everyone 

For a while now we've had our intranet CMS (content management system) set up so that the user can make a call to the W3 HTML validator service to check the code they've entered. 
I've made a cURL wrapper which gets the SOAP output of the validator and tells the user how many errors/warnings there are 

I was thinking of installing the W3 validator in a VM but then I found PHP's Tidy extension and it looks like it could do most of what I'm looking for. Apart from a few things:

1) I've had a dig through the options but I can't find a way to stop Tidy replacing unexpected tags, eg: 
Warning: replacing unexpected b by </b> 
I'd like Tidy to give me the warning/errors rather than actually replacing anything.

2) It seems Tidy ignores the case of tags and converts them all to lower-case.
Is there an option to also error/warn when tags are written in upper-case?

Is either of those possible with Tidy?
If not I guess I'm better off with the full validator

Thanks, B