DraKuL
3
Hi,
Sorry for the late response.
1 - I checked Avast! Settings and they havent given an option to delete the protection logs, you can only delete the Scan logs. Although I’m not sure if there is a way to do it manually, someone who has a more in-depth knowledge about Avast! might help you regarding this. However there is no harm in keeping the log files ;D the space on the hard drive it takes is negligible 
2 - try adding this as the site to block - ..exe Avast might add an extra * towards the end, but I just checked with 2 sites and it worked 
Also if you have Avast! Internet Security installed this can be done by changing the firewall profile to - public/ high risk zone. It doesnt allow any executables.
Cheers! 