Towing is interesting, but can now be griefed and abused by hiding siege engines so that defenders won't be able to have any at all. Also they're right now sometimes hidden at strange places (I know of a very cool garage).
Solution to that and to the picture: If siege weapons are moved outside of the keep area, they are destroyed.
The fact that players in the same realm are waiting for a player holding a siege weapon will get killed by a pet (or ready to take the engine if the holder leaves it (If that engine was not built by that player at that time)) is weird. I shouldn't blame the siege engines for it. But as the engines are so strong and most players are looking for the best possible rewards, this happens. Some might not heal, as they can snatch the cannon themselves instead.
I've also seen a player standing ready to tow an engine as soon as the holder gets ready to move back into the inner keep. He was standing mounted next to the engine as the outer door went from 100% to 0% and did steal it as the holder was getting mounted. It seems some players sees the cannons as the only thing playing for. It's a terrible way of playing, it helps no one, it doesn't help the realm one bit.
So why does this happen? The Siege engines are very powerful. Look at the top list of RRs, almost every player in the top farms RR mostly by camping siege weapons (I've done it myself when I lack the support I want for "playing"). By constantly spamming 600 dmg on 18 players (if you're good at it), you will get a ton of renown if any of those players dies (and many medals if you get kills). 5 AoE cannons hitting the same players will deal 3k dmg every 5 seconds.
My ideas: I know you've said this is part of more changes in RvR. But right now I think 18 hits (right?), is a bit much (I still think the original was powerful). With 9 hits there will still always be 5 engines deployed in keep sieges on both sides. I also think dodgable siege engines could be a solution (or maybe even both), with dodge, tanks gets one more task in sieges.
I've also heard you talking about a decay on engines, I can image something like 1% maxhp loss every 20 seconds. A siege weapon won't be up for more than 33 minutes and there is no need camping them. I think this would bring a little bit more life in RvR. Shouldn't keep sieges still be about the realms attacking and defending, rather than siege engines?
Finally I love the way you're using the ram as the major damage dealer to the door. Door melting is still faster with very big numbers, but it doesn't melt within 20 seconds. Also for more small scale, outside of prime time, keep sieges are possible. Oil is a good counter to it, right now it's strong, but outhealable if you're prepared, well balanced I'd say (except for the 'bugs' reported on github).
