Hello,
1. Unfortunately, you can only edit the filters in the Bet Sizes tab in Configuration -> Bet Sizing Categories. For postflop stats, you can also edit the hand strength filters for the Range tab and the board categories filters for the Boards tab:
2. For postflop stats, you can only insert a Postflop histogram, which will display hand strength:
Simply drag any postflop stat onto it:
3. Hand2Note 4 config files are not compatible with the older version. There is no option to convert the new version's config to Hand2Note 3, unfortunately.