I wonder if it its possible to tell CT not to make any hits and memory fragments whatsoever. I don't mean just hiding them on the matchboard but complete switch-off. If I change the matching type in the memory to "fuzzy", will it do the above?
Nope, it won't. But why would you want to do this?
Perhaps the Preferences on the Memory tab can be changed to achieve what you want to do.
E.g. see: Subsegment to Auto threshold at: https://dl.dropboxusercontent.com/u/509643/ct-wiki/cafetran.wikidot.com/the-memory-tab.html
> If I change the matching type in the memory to "fuzzy", will it do the above?
Yes, you will not see any hits - only segments and exact fragments that are present in your TM.