Recording everything would be fine, but if you want to take the time, certain things would be nice to have separately, so you don't have to search through hundreds or thousands of packets to find something.
For example, a log of you running through almost all of of Uladh to get Eiry's first enter messages would be nice, but finding that dialog amidst all the other packets would take some effort. It would be more comfortable to look through, by starting logging when you enter a new region, and stopping right after she's done, saving the log as something like "eiry first enter dialog dunbarton".
Logs of normal dungeons are generally not necessary, but we could use logs of special dungeons, like RP, quest dungeons, etc. Again, ideal would be segregated files, for entering the dungeon, cutscenes, boss fights, etc, but this is naturally harder to do in dungeons.
In short, we're thankful for any research data, and segregated logs are optimal, but not necessary. And it's always better to have a full log than to miss something^^ Videos shouldn't be necessary, especially if you split the logs up a little.