Throughout the question, you provide examples of programs you've tried and some specific concerns you have about your situation. That's great! Unfortunately, recommendations for off-site resources (including programs) are off-topic here, as noted by the closure reason. 

It is possible to ask questions that will probably require third-party software, but here, it looks like the question was closed because of the title ("Real-Time Sync Utility") and the opening sentence:

> I'm looking for something to synchronize my Computers with a NAS in the local network.

It's easy to forget to update the title after changing the body - I've missed it myself a couple times! - but people usually use the title to assess what the question is primarily about. Modifying the title to describe your situation would help.

You [did adjust](https://superuser.com/posts/1140617/revisions) the closing sentence, and that's good. A bit more wordsmithing in the rest of the question might be able to make it clear that you're not necessarily looking for a software recommendation. In fact, your question does have one reopen vote pending at the moment.

Though if you *are* looking for a software recommendation, we have a sister site for that: [Software Recommendations](https://softwarerecs.stackexchange.com/help/on-topic). Thanks to all the information you included, you have most of an SR.SE question already.