I started before there were soul stones, so I have several chars for different functions - mage, warrior, tamer, bard, crafter plus a skill holder to save on soulstones. The last one was created after soulstones and the 6th character slot were available.
Also have several accounts that I took over. Seems a waste to use them only for houses, so I use them for different templates like Thunter, thief, begger, herder, assassin, extra tamers for pet storage, spellweavers for the circle etc...
1 single character might be feasible if you can get enough soulstones. You'd save on having to power scroll multiple chars. But then, remember that you need to wait a day to re-use each soulstone. It's going to be a pain to switch to a crafter, get your bods/repair stuff then switch back to your warrior.