Yes, “choquer” has a negative meaning, though it can be used in the sense you meant in colloquial french. In your case, I would use “surprendre” or “étonner”, but it’s a bit less strong.

In your example, it feels (in both French and English) like ‘[I am so wild, such as rebel that] what I say may shock you’. Interestingly, in this context people will not say ‘ce que je dis est choquant’ (but may say ‘ce que je dis est peut-être choquant’) : only other people are genuinely ‘choquants’ (I am ‘peut-être choquant’, i.e. a rebel).