I don't know if you need to worry but you shouldn't assume that deactivating your account means your data is not there anymore.

I have deleted my FB account once and waited the amount of time they say is needed for data to be deleted. In fact, I stayed out of FB for >6 months. When I decided to create an account again using the same email address, at the first login, FB was ready to remind me of all the friends I "probably knew" (sure enough, they were all people I had added as friends before deleting the account). So that information is unlikely to be deleted.

To get a somewhat vanilla experience I had to create an account using a different email address. Then it behaved as not knowing me (too much).

Yes. I deactivated an account per their instructions for permanently removing an account over a year ago and haven't logged into it and it's still active. The information on it is still available.

Facebook has also reset all of my account's policy settings to the most public options twice since I've been on facebook. My posts kept their privacy settings but everything else, my friends list, likes, etc become public instead of only visible to myself. I suspect it was a bug related to data migration since both times it happened during site upgrades.

Still, I do not trust facebook with anything I do, ever. I assume it's just as public as the information on my blog. I aggressively censor posts and tags because of that.

I tried deleting an account recently. It was surprisingly easy. You just had to find the right page and push delete.

Now, my account hasn't gone poof yet (it takes 2 weeks, they say), but I'm optimistic.