Just a note on the disbudding paste - BH won't use it and our vet backs him up. Apparently it's really difficult to completely and only cover the horn bud with only and exactly enough paste to burn it off permanently - and not spill over onto the surrounding flesh and/or keep going and penetrate into the sinuses below... ugh.
I have only ever been close to one Highland - he was a steer and more about him in a mo. What we hear about Highlands and aggression is that the mothers are extremely protective of their calves and can be extremely dangerous in those circumstances - not cattle you would keep on a public footpath!
Back to the Highland steer; he was a pet on an organic beef and arable farm I worked on. The main herd was purebred Aberdeen Angus, consisting of 66 cows, their followers and 3 bulls. I helped them on TB test day. All the cattle were routinely run out through the race and crush every time they came in, so were all really calm and used to following each other through there. After the Angus herd, the Highland steer then had to be roped and tied, which the owner said he would do as it was his steer and he knew him. (They couldn't use the race and crush as it wasn't designed for Highland horns.) There followed a dance in which the steer gently and slowly dodged the rope and his owner, while the owner described balletic figures attempting to get a rope over one of those metre-long horns. Eventually the boy was roped, tied, his lumps measured - no reaction, thank goodness - and freed. The 66 cows, all their followers and the three bulls had taken about an hour and three-quarters. The single Highland steer took a further hour and ten minutes!.