I'm sure the current state of raiding was just a band aid, however, I would like to post a few suggestions I've come up with through ~50 hours of Conan and various other PvP games.
The current system means you can not raid anyone with at least 4 walls until you are level 30, and at this point the people you can raid are hopelessly below you and can not possibly fight back. After this point, you can be doing literally anything else, run by some guy with a Tier 1 base, and decided to pop in for a visit, because the weapon or tools you're carrying by default can wreck his base.
The first most important step is to remove the ability to damage buildings from "standard" weapons, things like swords and spears shouldn't be able to damage walls or crafting stations. This way a raid is actually pre-meditated and planned with costs and benefit analysis rather than just "Oh a thing, let's go mess with it"
Following this at each Tier implement two new weapons, either as their own crafting recipes or learned with the foundation recipe for the tier. A "Stonebreaker Hammer" and a "Breaching axe", a Stonebreaker hammer can be used to smash foundations and walls of the same tier or lower, while the Breaching Axe can be used to knock down doors, and destroy chests / crafting stations. Both of these tools would have to be quite heavy, so it is a conscious decision to take raiding equipment, and they cannot be carried all the time "just in case". They should cost about equivalent to what they can destroy, and may only be repaired at a crafting station, so one hammer can not destroy an entire base.
My final suggestion, would be to add a "broken" state for crafting stations and possibly building materials rather than simply disappearing when destroyed. This way when you are raided, it is possible to actually rebuild the way things were at a slightly reduced cost, rather than having too completely start from scratch with everything that was lost.