Is it safe to use Google Docs or similar cloud services to store our IP and confidential documents?

Technically ... no. There was a recent report which postulated how certain TLAs might have pre-computed some matrices along with other tricks to weaken the Diffie-Hellman based secret key exchange behind https, VPNs and SSH. However, as a practical measure, would any state-level agency commit sufficient resources to look at information which whilst time-sensitive, has nearly zero value after you establish the company (business plans change all the time)? It all comes down to risk management, the chances of an event happening balancing against potential losses and the cost to mitigate. All encryption does is adds delay so that perhaps a human has time to notice the penetration. Even if you want to up from consumer grade protection (current) to commercial (selective services ... email me privately and I can advise based on your needs like secure email) or even banking grade, someone somewhere will find a weak spot (social engineering) if determined enough. But in general, on the overall scale of risks in managing trade secrets, it is more likely that potential hires or subcontractors rather than random strangers are likely to be the culprits for IP leakage.

As for google "owning" your data, you're thinking of the terms of services for social networking sites or anywhere there is user-contributed content. Google does analyse your pattern of access to train their predictive software but under their data liberation front policy is that you the user can take away that data source at your whim. Frankly investors don't care about these operational issues (unless you're an info-sec startup) but your ability to execute on what you promise. Try to get traction numbers that are worth boosting about before worrying about hiding the outcome.