Triggering events? Summoning enemies? Let’s spice up the game!

My small group (2-5) and I have several impenetrable bases in different biomes! But it gets a little boring, you know?

Maybe it's our numbers, but since around the Elder no raid can even get past the perimeter, let alone threaten us. (Aside from the flying raids, which regularly kill our pigs. That is not particularly fun to battle against though.)

I think it's great people love the exploration and crafting in the game, and many don't like getting raided at all. But for us is there any way to… test the helm's deep defenses a little? Something like…

1) Can we spawn a boss and lure it away from the totem and over to the base?

2) Can we trigger a raid event, or somehow cause multiple raids to happen at once?

3) Can we build some structures or layout that encourage raids to attack our base more than the standard "Every 40 minutes, 20% chance of raid"?

4) I know this isn't a thing, but I'd love to see some buildable structure that summons large waves of enemies. Or to make the graydwarf nests, draugr spawners, etc buildable.

Cheers