Osage A ... Yes, you are right that Bogota is reputed to be a little more "cold" in the interpersonal relationships, but I believe that is mostly between Colombians and other Colombians, and as you rightly suggest, is usually found in the larger metropolis or capital cities anywhere. Whether this is because of the competitive nature between fellow countrymen, I'm not sure. But I do believe from my own experiences that where extranjeros are concerned, especially English speaking, from the USA or UK, they go out of their way to get to know you and be friendly, if only you allow them into your life. You have to integrate with your community, or you may not experience their warmth. Everywhere I go people want to stop and talk, get to know me, invite me into their lives, and they genuinely want to be friends. If they think I have a problem, they are immediately wanting to help. I have never experienced that kind of genuine welcome and friendship in any other country in my life. In large cities, its easy to miss those opportunities and signals, as everything runs on a fast pace, and people have little time to stop and talk. But in your own local area, the local community is where you will find it, whether its your neighbours, the local shops, cafes, and when I have been in the same shop a couple of times, they recognise me, and new friendships start to form very quickly. I'm sure its the same in the smaller towns and cities too, but in Bogota it may not be obvious at first, but its certainly there.
On the question of zancudos/mosquitoes, yes, I agree with you both, you will find mosquitoes in Bogota too. I usually get maybe half a dozen a year in my apartment, (I'm fairly high up) which I quickly dispose of. Some areas that have a lot of standing water around get many more. But there are many strains of mosquito, and the actual strain of mosquito that most commonly hosts the viruses that I mentioned, (the Aedes mosquito) don't really like the higher and colder altitudes, and when they get to about 5,500 feet, really don't want to be there. In fact, the higher they go, they have difficulty breeding too, so in Bogota, which is 8,600 feet, and certainly where CCC lives at 9,500 feet, its free of that particular strain. Now I am sure that if someone travels to the low altitudes, gets bitten by an Aedes mosquito, then returns to Bogota or ipiales, and then gets bitten again by a local strain, then yes, its possible to transmit the disease. But I am given to understand that the likelihood and risk is actually quite low. I am also told that of those who are diagnosed with those diseases in Bogota, by far the majority have recently been to the low areas where the Aedes strain lives. But of course, anything is possible. Never say never.
And yeah, sorry for the "off topic" . But it makes a change from all those who post thousand upon thousand of posts about how good Medellin is.  Bogota is also great, at least to me, hahaha.