I've just checked, and most of my migrants are competent (level 3), there is one who is competent in melee, and novice in crossbow (he will form my special forces), and there are two who are adept (level 7) with melee (spear and mace). Only these two had any significant kill list upon arrival, 168 and 163. All others have from zero to eight kills. No dabblers. Most of dwarves have level 1 in dodging, armour using and shields. The one trained in melee and crossbow is level 2 dodger, and the adept fighters are level 5/level 6 in these three skills, with exact number of EXP points (like 4700 for level 6 and 4300 for level 5 and 1800 for level 3 and so on). Some marksdwarves have ambusher skills, I think they were rangers, I got a number of rangers (in one wave there were three of them, they started hunting bears almost immediately after arriving). Interestingly, the new migrants have 0 EXP in Archery, all archery EXP they get are generated during hunting with crossbow, after they came. This may be a bug. Alternatively, they were trained in dwarf shooting simulators, without wasting any ammo.
As for magma pipe, this is the first time I saw one. I made a very limited number of embarks, because I prefer to get whatever I can from whatever I have, so despite hours spent in DF I haven't seen many interesting things.