Seems like the issues with node vandalization is really about balance. It's too easy to vandalize a node, too hard to defend one, and it takes too long for them to recover. I don't think HnH gets a lot of dev time allotment from Jorbtar, so any modification of the status quo need to be weighted accordingly.
So Ideally, because I like more content, I'd like to see special purpose idols added which would increase the hhp penalty for specific crimes within a certain radius around them (assuming same claim and non-stacking, because building 19 million idols is not fun, imo). A straight QL-based hhp add. Could even have special idols that cause a warning fire to light by the village idol or a gong to sound or something more.. germanic... A great horn sounding? Not up to speed on my period lore. Some idols could extend the duration of related scents left in their radius, increase related crime action timers, etc.. Anyway, the idol could then be protected by walls more efficiently than giant anti-immigration walls

. Idol spacing might be based on Cha (could use more cha affects), i.e. I can only put 1 idol ever Xk / sqrt(cha/10) tiles from another idol -- this prevents the desire/need for overlapping backup idols (you can only place them so close together). It also creates more territory effects. Note that it's based on the placer's Cha, so even if some newb places an idol on another island near you, if your cha is awesome, you can still place your idol (the inverse is not true). Now you can have economic warfare with idol placing as well as claims.
Then, you add some new idols under the War Speaker skill which would cancel these idol effects within their range (these idol types do not interact in the placement limiting system above). Radius of effect would be based on their QL, they would take a certain amount of time to build up their power (based on type), and last a certain amount of time before degrading (duration based on time build up), at something between a 4:1 and 8:1 ratio. So 4 hours charging up gives you 30m-1h to go mad on someone's plot without being affected by defensive idols (i.e. no *increased* crime penalties, just the base scents/penalties).
Additionally, some numen based ability to pray for node recovery sounds reasonable to me as well (although I foresee the tradition maxed alt abuse here, so maybe limited by your ancestor's appropriate skill-surv in most cases. At least then the abused alt would be crafted at some cost

). Also for some node types, for instance soil quality, it feels like you could create a mechanic to manually do this (for instance, I bring a higher than current ql earthworm(s) and use it on a tile to improve the restoration rate of its soil quality up to the ql of the earthworm). Similar techniques could be added for other node types potentially (fish for fish nodes... some sort of rain dance for clay nodes and water nodes--clay is largely about silt and the accumulation of certain mixes of minerals from rainfall/drainage/waterflow...).
But that all seems far too involved, so, how about just a slower timer when harvesting criminally, some sort of debuff/stacking damage to make it harder to alt vandalize effectively. Debuff would prevent logging out and would increase hhp cost of further vandalization. At least this way it would be very time consuming to do with a new alt. Certain tools (Sledgehammers, Rams, etc.) would be immune to such effects (they arn't used for node vandalization anyway). If you arn't even willing to claim the node, than it's fair game. Also a sampling skill that would tell you what ql a tile was without actually harvesting (and damaging) the node would be great (but off topic). I do feel like node quality deterioration being a singular value over the entire node is an undesirable mechanic regardless of this issue, but from a programmatic perspective I think it would be costly to fix (node system allows a great deal of memory savings for their map). Any fix to that would probably break our dev budget. (But if Jorbtar read this, they might consider using "depletion" nodes, grouping depletion on specific tiles into "subnodes" linked to the base node for localized depleition, and performing some quick computations to calculate effective ql on the tile. Depletion nodes could be merged (grown) as depletion became more systemic, and the system wouldn't need to be "perfect", just representative, and therin could use the existing node mechanics.).
Other comments: Depending on the type of clay, it does restore itself naturally in the same manner as it occurred in the first place, depending on the type of clay in question (there are many, many types). Some clay types can be manufactured as well, although I'm personally ignorant of the period techniques for this. Water quality is pretty artificial in HnH, but typically is not "drained" by its use, only polluted potentially. Soil quality is also complicated and depends on issues such as weather, what is growing in that soil and what is left to die and turn to soil on that ground, etc. Things like "Stone quality" really aught to be more like metal, in that they are non-renewable resources--so much stone and then its gone if we're trying to be "realistic". The only real sources of "new" metal/stone would be volcanic activity from the Earth's core (and meteorites I suppose). But with all these sorts of topics there is a questions between "realism", game play and fun

.
The problem with the Burg's surv suggestion that I see is that it's abusable. Say I have a ql 90 node, I harvest it with an 89 surv character so it doesn't degrade. If it does degrade, than where are you putting the line? (Because honestly the alt cost for even 50 surv is pretty trivial) Meanwhile, one can edge nibble to vandalize the node with little extra effort (or if you change it so they can't, it opens up the possibility of yet another kind of abuse). In my mind, the griefing/conflict aspects of this game are intended to be balanced by accountability. Anything you can do with a throw away alt therein subverts the spirit of conflict in the game (particularly if there does not exist any mechanic to prevent it). In the case of node vandalization, you could establish extremely broad walls/rafts and claims, so an argument that it is preventable could be made. Personally I do not feel that prevention mechanic on its own is reasonable, or fun

(or sufficient in other words).