Hmm you make me to think about it a little.
There is something like etconsole.txt file which is created when you toogle /logfile "1".It store all your console data/, ofc without breaks everything in one line but good script would find necessery data.
One problem is that whole data is stored after game closing if I understand it well.
Second problem is no matter which code language you will use to write script which would search for special text and executing file which will do something as a reaction for it (for example clicking some button which is binded to executing it) you can't execute script from ET you will have to execute it as a different program. I don't know if it would be possible to make lua script and attach it from player side to the game, coz these script are server side scripts even when ETPro/NQ mods are supporting LUA.
So in summary:
- logfile is created after closing game
- in logfile there aren't onscreen messages, only this what was in console (usually text about unbalanced teams is displayed on screen) and I don't know if you can switch it to console, I don't think so, coz it also is server side message.
- script what you will have to create wouldn't be (probably) connected with et game client, but just different program which will affect et game.
And generally even if first 2 points would be possible to get trough them, with 3rd point it start to be a bit too complicated for normal ET player. Making it just for myself is stupid, if I would create something like that I would share with it with others. But I don't think many people will download additional script to have magnificient class selector script which would work no matter of situation.
Maybe you have more ideas or something what I wrote above is not true?
EDIT: wait x; don't block anything. This command stop the executed line for x FPS, and during the wait period it trigger action which will be made during this period, so for example if you u will make wait 1000 and start shooting, u will shoot to end of wait period - something like that, but in case of low duration 10-25 you wouldn't be able to do anything.