Butane is one of the cleanest burning natural gases, which is why there are numerous applications in which it is used.
Ligther or no lighter you'll still be getting medicated. There have been studies pertaining to cannabis burning at lower temperatures where various cannabinoids are supposedly more active at these lower temperatures. Whether this is true or not, you can get the same "effects" of low temperatures by using a lighter so that it is further away from the herb, as I believe FDD mentioned.
The #1 reason why people (should) use wick/glass rods is for taste. Personally, I prefer using glass rods for the best taste, as I can notice the taste of the hemp wick a lot in my hits which sometimes overpowers the taste of my bud. Have only tried I-tal wick and yes, I think it kinda sucks; the hits are WAY harsh, more so than when using a lighter I think. I put in a request for the free humbolt wick...hopefully it will be better than I-tal.