If you had made a backup of your. iPad you could restore it to the earlier setup. However, Documents that have been opened in 1.7 will not open in 1.6. If you don't have a backup then unfortunately you are stuck on 1.7.
I'd also suggest turning off auto updates and then you have the option of waiting a few weeks before updating, rather than being an early adopter, as there are usually teething issues after any major release.
Clearly there are a few (annoying) behaviours evident in the latest major release, and from a user perspective this can be extremely frustrating but we need to at least give devs a chance to fix the issues. They will release an update before too long and then we can get back to enjoying editing on our. iPads.