Hi Greg,
Let me start by stating that Method’s functionality was designed and built around syncing with QuickBooks (QB). The best recommendation that I can give you is to continue syncing with your QB file, even if you are not keeping your transactions up-to-date. This will ensure that Method continues to function the way that it is intended to.
Alternatively, you can stop syncing, but issues may arise. You should have no problems viewing data that is already in Method. Entering new data is where you can potentially run into issues. Problems can occur that require you to perform a synchronization with QB to resolve. An example of this would be a table becoming locked.
If you are going to go the route of using Method without syncing, keep an installation of QB and your file handy on one of your computers. This does not have to be your server. If you end up having to perform a sync for any reason, you will at least be prepared to do so.
I hope this helps.
-Audisho