Correct answer for No2. It's a twin Madsen set up for ant-aircraft work.
Near enough for No3, it's actually an M-8 Greyhound, converted in 1993 by one of the Colombian Army's MP battalions as an anti-mining point vehicle for road convoys. Like a lot of places with long running insurgencies, Colombia has and will have for decades a big problem with landmines. Here's another photo.