Removing the mod

You need to uncheck the disable vanilla ai before removing the mod. Only needed for version below 0.18.13

Building Safety not working

Did you enable the global setting of
Safety: Enable Building Safety
in addition to the buildings you actually want to be safe.

Rampant using lots of memory when using new enemies

Adds news enemies that will be dispersed over the world. This increases the RAM requirements. With 1 variation for each biter, worm, and nest and 5 tiers expect upto a 2GB RAM increase. With 20 variations and 10 tiers set expect up to 9GB RAM increase. Variations add randominess to each tier of biter, worms, or nests. Tiers are the power level of the biters.

Why are the new enemies in the data-final-update and not data.lua like I expect it to be

Because the time required to load a fully modded out game would go from the top minute that it is now to 10 minutes with all the new enemies enabled.

Rampant does not create attack waves when you chop down trees.

That is caused by
https://mods.factorio.com/mod/Natural_Evolution_Enemies

Rampant does not prevent building near spawners.

That is caused by
https://mods.factorio.com/mod/aai-programmable-vehicles

Factions or all new enemies can be removed using the console commands

/rampantRemoveNewEnemies
/rampantRemoveFaction