First, clans.  Most people in the game want to either get in an official clan, or start their own.  Most don't even know WHY they want to join a clan, they want in just because clan's exist.  The same applies to subpaths, people have no idea why they want to join, with the exception of some that study the subpath and find it fits their personality..

For a clan, the most important reason to join is to be part of a community.  A clan is a large family with the Primogen as a sort of father or mother to the clan.  A clan can take a major amount of your time and resources.  For instance, recently I donated a net value of over 2,000,000 coins in goods and money to my clan.  Why did I do this?  Two reasons, one, I like my clan and they will use these funds and items to make clan events for the enjoyment of other members, clan hunts, poetry contests, carnages, and more.  Second, I got frustrated with saving up the money to buy Sunclothes and then not being able to find any to purchase.  Rather than getting mad about it, I donated to my clan to keep my spirits up.

If you plan to join a clan OR a subpath, remember, neither one takes criminals.  It is best to obey the laws of the land and avoid brands in any case, but even more important if you plan to join a clan or subpath.  If you already have a criminal branding, don't even bother to apply to a clan or subpath until you get the brand removed.  This is very expensive as only the chonguns can do this and it takes an angels tear, keyset, and more to get the brand removed.

Sub paths, like clans, you join to be part of a community.  The biggest difference between a clan and a subpath is that anyone can join a clan without any special knowledge.  A clan simply wants honorable people with good intentions.  Subpaths on the other hand take special knowledge and a special tempernment.  For instance, if you aren't interested in reading the future, there is no point in becoming a Diviner.  If you aren't interested in being a story teller, Muse is not for you, etc.

The subpaths give you the opportunity to fit your personality to a particular style of roleplaying.  The spells are not worth your time in comparison to NPC run sub paths, as the NPC sub paths have much better attack and defense spells. However, if you want to get the feeling of being a merchant, having others come to you for prices, for a fair deal, etc.. Then perhaps the merchant subpath is for you.

There are many fine roleplayers in the game that are not in either a clan nor a subpath.  For one thing, they don't want to take the time that are required to be in either a clan or a subpath, but more important, some people don't fit any of the subpaths or clans.  For instance someone whose simple goal is to get into the political arena, or who only wants to be a carnage host or helper, may not want to also spend time doing clan or subpath activities.

Think hard before applying to either a clan or subpath.  What is your goal in the game?  Are you out for yourself, do you want to be the richest superwasabi in the game? If so, a clan or subpath isn't for you.  Do you want the security of a family to help you out?  You have two choices.  I personally have so many sisters, brothers, sons, grandsons etc.. in the game I wouldn't actually need a clan for family, but on the other hand, the clan gives a sense of stability, something that will always be there even if everyone I know were to leave the game.