1. The option has been there for the time you have been an avast user - To change the default settings - right click the avast 'a' icon, Program Settings, Common section, Show Explorer Extension Results.
2. That too has been there in the avast settings, I can't recall from memory as I'm using avast 5.0.418, but I think it is in avast Settings, Update (Basic) Details not to show the notification. You will have to see if you can find it.
3. That too as a pro user is also available to you as you can set up auto actions on detections from the Enhanced User Interface (EUI). I can't point you in the area of the EUI as I have never used it.
Personally I would suggest that you update to avast 5.0, if you have winXP, Vista or win7.
- Download avast! 5 Pro,
http://www.avast.com/en-gb/pro-antivirus#tab4, click the download button or try this direct link -
http://files.avast.com/iavs5x/setup_av_pro_eng.exe.
If you install over the top of 4.8 it should convert your 4.8 pro license details otherwise if you do a clean install you have to convert your old license and register it.
- avast! 5 Pro license convert from 4.8 Pro license. Try
http://www.avast.com/resend-license.php now, fill in the form giving your email and 4.8 Pro License key and they will send the new license file to you (presumably it will check you have a legit 4.8 Pro license first).
How to register avast 5 pro on page 7 - 8
http://www.avast.com/documentation/quick-start-guide-pro-en-ww.pdf also see
http://support.avast.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=459.