MP servers blocking the use of Tacview? That sounds rather paranoid and is, to my knowledge, also futile. As DCS automatically records a track of every MP session, you could simply disable Tacview while actually playing, but reenable it for the replay of the track. A bit tedious, but unless servers can also forbid the recording of DCS tracks, there is nothing keeping you from using Tacview for flight analysis if you really want.
There are of course legitimate reasons for disabling the data export functionality which Tacview makes use of.
Just start it up, and explore its menus by clicking on the big icons at the top. Very small icons in the lower right corner indicate for which sims recording is enabled. Just fly a mission in your favourite flyable, and you should find an ACMI file in the recording folder (which you can set from the menus). Or just download a demo ACMI file from the website. Open it and explore!
I downloaded this after reading this thread, and i think this tool is amazing. Having a chance to take a look at what went wrong, why you got shot down etc is extremely valuable. I can see this improving the performance of any player who bothers to review their sorties after the fact.
As well, i discovered another handy use... I was just playing on the =STP= server, and after spontaneously blowing up on the runway, i wanted to know what killed me. Lo and behold...