1) it shows the servererror message not correctly (i use validation tooltips for spry)
the captcha validation is not a spry validation, the you cannot use Validation tooltips for spry to style the captcha error message, it can only style spry validation errors
2) it does not check the captcha value entered before i send the form
Yes, that is the way server validation works, the form needs to be set to the server in order for the server to perform the validation.
if validation fails, it returns you back to the form to correct the problem.
3) no progress bar, no email message
I am seeing the progress bar, but the validation is failing so the email wont be sent, If you need further assistance, send a copy of the page.