As an experienced penetration tester and someone who has actively sought out critical vulnerabilities in major companies, I am uniquely equipped to tailor a secure Nextcloud setup specifically for your QNAP NAS. Although my research is focused on hacking, it also extensively covers network security, ensuring the utmost protection for your data during its syncing and sharing process.
In addition, my skillset includes Python, Django, and Flask - which will come in handy in automating tasks as well as implementing SSL/TLS encryption for Nextcloud. And when it comes to your desired requirement of proficiency with configuring secure file sharing in cloud environments, my past experience will be invaluable.
Lastly, I understand the importance of deadlines and effective communication. So if you're looking for top-tier web and computer security skills combined with a friendly yet professional demeanor, then I'm confident that I'll exceed your expectations. Let's take your QNAP NAS Nextcloud setup to the next level together! Do reach out to ensure a well-protected solution for all your file syncing-and-sharing needs. Thank you.