Well, it's not as easy as you might think... I have to search all the sources for the occurrences, then find out where it's used and then try to guess what the hell does it really do
So, don't take my answer for 100% correct.
Section [InetWD]
1. Sleep (Default: 40000 (40 seconds))
- The interval of pinging the updating servers (to detect internet connection)
Section [UserInterface]
1. ErrorDlgTimeout (Default: 10000)
- some timeout for error dialog... have honestly no idea if/where it's used
2. RespondTimeout (Default: 30)
- not used
3. VRDBBalloonShown (Default: 1)
- specifies whether the initial VRDB baloon (shown once after the installation) was already shown
4. ScrollResults (Default: 1)
- corresponds to Enhanced User Interface setting: "Scroll session results"
Section [AAVM]
1. SuppressExpirationWarning (Default: 0)
- not used in avast! Home/Pro
2. NeverShowInfo (Default: 0)
- suppresses display of (some) info messages, I think (silent mode for updates?)
3. LogDiskChanges (Default: 0)
- seems to log drive add/removal into event log, if set
4. LogStart (Default: 0)
- logs resident protection start into event log, if set
5. GradientStepMsg (Default: 20)
6. GradientStepInfo (Default: 50)
- didn't find any "GradientStepMsg" or "GradientStepInfo" occurrence, only "GradientStep", which has something to do with the color gradient of avast! info messages
7. EventLogAnalysed (Default: 1)
- not used anymore
Which are the values for the old [ODBC] section that are still working?
- none, I guess