Safest way to copy files to AirPort Disk from the command-line?
Using rsync is likely your best option and the flags enumerated in your question are reasonable.

An alternative tool to use would be dd. This tool approaches the copying process at a lower level and is often promoted where exact copies of disks are required. The dd manual has all the options. I prefer rsync for its relative simplicity.

Post Copy Check

You may want to extend your script to perform a post-rsync check. Use another tool, such as diff to compare the source and destination folders are equivalent.

If diff does not provide the incremental control you seek, consider comparing the md5 hashes from the source and destination's contents. See How can I calculate an md5 checksum of a directory?