I just revised the combat method to hopefully stop attempting to attack things when they are already in combat. The problem is there is no setBreakCondition method for InteractionEvent, this means that after I do checks to see if the target is viable(not under attack, etc) and the interaction is called the bot will attempt to interact with the target until the target is clicked, after that it will work fine and attempt to attack the druid attacking it. The work around I've found should work, the problem is I can't test it yet because of the bug hunsilan reported.
As far as the memory usage for walking, are you having the same issue as before? Does the memory use just continue to increase till you get an OutOfMemory error? That amount of memory usage is fine for web being used, the script normally sits around the high 300MBs, low 400MBs for me, an increase of 200MB-300MB is actually great according to Alek's post in my bug report on web walking.
Just found this as well while testing a revised combat method, this is not a bug with the script itself. It occurs whenever getLastHit() is needed, such as when I need to determine if the target is already under attack or if I need to grab the target's health, I have reported it under the bugs subforum and am waiting on a mod to approve the post.