Dragonic Righthouse is an useless buff, for 4SP you get +12%E atk & 200 E.Def, it can be good, but i don't use it because 4SP are very important in a SK build.
Put them wherever you want, but you have to know that people who say "blabla its best build bcause someone with full +15 who pyd 2000$ on game win budokai with it" are just noob posts, normally the true power of a SK is his Steal Life, when you place it after a debuff -550def E/P it'll do pretty good DOT, plus giving you 330lp each 2seconds, so only by this skill you have to make yourself Invincible, for exemple getting full %LP effects gears (wich will reducs damages of 45% if you got 45% for exemple) & also some debuffs ? like i use vs others SK, i can make higher damages to them with bold strike ( & same defense ) with a lvl 58 axe + 8 while they got lvl 60 one + 10.
You have to think about a build, about every skills there is, then you'll find.