We have 2 types of the Kaffir lime trees. We have the one variety that does not have thorns. We have another that has thorns that are damn near 2" long and are stiff and could be used as a weapon. They both bear fruit that is never is used (Albeit I cut them and toss in the bathroom for a nice smell). My wife does however use 3 or 4 leaves from time to time in various dishes.
We have 5 regular old lime trees. My FIL grafted them from the large one we have but they produce very few limes and small. I recently bought 2 lemon trees and 1 has a lemon already.
AHHHHHH Yes...Mot Dang (Red Ants). Brutal bastards. Relentless. I just trimmed my Lumyai trees way back and they assaulted all of us. Bite is annoying and feels like your getting a shot. Thank god no venom. Our trees had 3 BIG nests. My FIL cut each one off into a bag and took the eggs and gave them to his neighbor lady friend. From my wife she has never eaten bugs and my FIL says the same. I have zero need to try and won't.
Actually that does work and if you do it enough they will look elsewhere to nest up but they still will raid your yard. They are an important part of the eco system for pollinating trees here along with the bees. The good thing is they do not enter houses. They really do not want to be bothered.