Bit of a tricky one!  I used to work for a big company who used the HR people & appraisal system to hit you over the head at bonus time. Having said that there were some excellent HR people who made voicing concerns a lot easier!

Firstly I'd make yourself available and approachable at all functions and get togethers.  If necessary commandeer a meeting room away from the CEO's office - possibly on the basis of it being a drop in session?

Secondly, is there a way to make the surveys less traceable (e.g. use an online survey)?  Once you have this info it will be easier to confront your CEO and suggest your solutions to the problem.  

Specific issues with the CEO are harder to deal with - is there any reason for her feeling insecure?  Would training help?  

Good luck!