Treasure chests that can picked spawn throughout the world that do not require a map. Then there are separate buried chests for which you need the map. In order for these to spawn, you have to be holding the map and other players can't see or grab it.

Regular chests offer lower quality items...although both kinds are mostly junk. Map chests can contain drop set pieces from that zone, malachite shards or rare drops of paintings for the houses. If you really want to go map hunting, maps can be found for very cheap in guild stores under other...trophies.

The only concern about working craft skills up fast is how it alters the node spawns. A smith node will spawn a out 50/60 according to 1. your smith rank (not level, but how many points spent in the first passive) and 2. Your character level. So, if you are a level 5 toon and have worked smithing up to 50 and spent points to make it max rank, that toon would find iron and rubedite ore nodes. So they'd only be hurt if you really wanted to farm something in the middle.

A second consideration is daily writs, which reward gold mats and other perks. These spawn for locations based on your rank in that skill. Generally it's easier to keep writs "together" if you're doing them, meaning you keep your clot, smith and wood ranks close together so that writs drop in the same zone.

But other than these minor inconveniences, you can level your trade skills as fast as you like.