| No it is very important.
Omni is the 'easiest' and most popular. Several items in the game are 'sided' for you to wear them. Also most of the guides are written for Omni etc..
Neutral would be ok because they can wear a decent amount of stuff that is designed to be half sided. By half sided I mean it says 'not clan' or 'not omni' so you can be one side OR neutral and wear it. Some quest items are like that and you can do the clan quest AND the omni quest and get both items. Those are very few though.
Basically if you are starting up go Omni on RK1 and get up with us and things will be a lot easier. If you want a challenge later you can actually switch to Clan but be prepared to lose the use of any Omni sided items.
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