If you're not hard core tournament players, then don't follow the rules to the letter. Choose what most or all of you feel comfortable with. But, at the same time, learn the proper rules. There's a chance that later on you could inject more of the proper rules into your group.
I think you should learn to use the serving hole. Setting the ball in the middle to start play was a rule that was forced on us by a non US entity and could conceivably be retracted. If it is, then you will already know how to serve. It's an acquired skill. If it's not, anyone can place the ball in the middle.
Eventually, you need to accept the five row shots. It will make better players out of you. The two points for a clean shot is a sure fire way to start an argument. If I shoot long and it cuts back to the inside hole, who's to say I didn't plan it? On the other hand, if I intentionally shoot a middle and the goalie gets a piece of it but not enough to keep it out of the goal, why should it count any less than the slop cutback? And where do you draw the line if it barely grazes a goalie or he blocks it solid but still goes in? And what about banks or masse shots? If they go in the goal, how do you define clean vs slop?
As for rotating players: When we used to rotate, we let the winners stay on but they had to split up. The two new players would flip a coin to see who they played with. We used to gamble this way but all players involved need to be reasonably close in skill level. If not, then let the losers stay on and let them split up. That way they get more practice and don't usually take such a beating in the gambling.
Whatever you do, try to keep everyone involved in your rule making and the format you try to play.
If you're interested in a double elimination brackets, I uploaded a couple on Open Office you can try. It's a stripped down version you can run onscreen. It's not made to print and manually write in the results. Open Office is free, which is why I used it. You can't complain about the price.
For a 16 team bracket:
http://templates.services.openoffice.org/en/node/4977For an 8 team bracket:
http://templates.services.openoffice.org/en/node/4975