Oooh, oooh! I'm sure I can help you out here, I've been maining strike forever it seems now.
-You defiantly need 2 or 3 Strike Ninja. You can either go for a Return build with it, or a build where Strike Ninja is support.
-Great dark monsters inclue Mystic Tomato, Don Zaloog, Jinzo, Newdoria, and Sangan.
-You could use some sort of discarding method such as Morphing Jar, or Magical Merchant to mass darks to the grave quickly.
-Warriors supported by Reinforcement of the Army.
-Most of the staples besides perhaps Mystical Space Typhoon, or Premature Burial.
-You could use great tribute monsters like Dark Magician of Chaos for a ninja-based deck.
-I've seen strike in different deck strategies on metagame.com over and over, and they are basically what I'm describing except with different ideas. You really ought to go there and do a strike search, there's great articles to learn from.
-Doesn't need many traps.
-Usually needs more than 40 cards.