3 to 5 percent edge are high but this do depend on the game too .
good games like slots usuall have higher edge but i better play on games or on site that has 1 percent or lower edges than that although this wont mean that i can be a winner now but atleast i have more chance than ever.
your shared strats to beat the house is okay , i have tried this and seen many gamblers try that but is that all a myth ? because theres that time that we are gonna loose after trying these strats .
House edge is simply the amount the house rakes in to cover their costs and plan for new ventures. Where the house makes it's real money is where the punters roll their winning back into vet more wagers at whatever game they are playing - even if they have a big win and eventually the gambler looses out. Always know when to fold/cash in/walk away.