If you have all those fundamentals in place, does it matter how many steps you take?
Does it matter if you use one hand or two?
Does it matter if you are a stroker or a cranker?
Or does it matter it you throw a hook or a back-up ball (reverse hook)?
You need to be comfortable in your own style when you're bowling and to this point, I want you to remember that, "you are unique, just like everyone else."
Let's take a look at some famous bowlers from the past and present who exemplify their own styles; but, still had all the basics "down pat:"
Lou Campi - "Wrong Foot Louie" was a right-hander who ended up on the right foot instead of the left.
Lee Juuglard - used a 3-step approach and a used a bowling grip that was finger-tip for the middle finger and conventional-grip for his ring finger.
Harry Smith - who not only was constantly moving during his starting stance, but, also took an unusually long hop after his final step.
Don Carter - how can anyone forget his bent elbow, "no backswing" style and how he seemed to push the ball down the lane with the palm of his hand?
Billy Hardwick - he used his index finger and middle finger rather than the "regular" middle finger and ring finger. On top of that, he threw a full-roller.
Mark Roth - was it a 6-step or 7-step approach and having to "screw" his thumb into the ball?
Jason Belmonte - the guy who uses both hands rather than letting one arm swing the ball.
James Cripps - the backwards bowler.
Walter Ray Williams and Earl Anthony - strokers.
Robert Smith and Jason Couch - crankers.
Chris Barnes - he's called a "tweener," which is nothing more than between a stroker and a cranker.
As far as "no thumbhole, fingers only" and "reverse hook (back-up)" bowlers, if you bowl often enough, you will see some very successful people at the local level who do use those styles.
I currently know of several "no thumbhole" and just as many "back-up" style bowlers who average 200 and beyond.
I could go on-and-on giving examples of people who carry high averages with a vast array of styles.
When you get down to the final analysis, though, they all developed their game around the sound, basic fundamentals of the sport. (See the first paragraph of this article.)
When you decide that you want to take your game to a higher level, keep in mind that "substance rather than style" will be your key to attaining that higher average.
Concentrate on getting your balance, timing, and leverage sharpened to the highest level possible.
Be comfortable in your own uniqueness and you'll be more successful than if you try to copy someone else's form.
Think of it this way, "will you enjoy yourself more it you can do it your way or by being someone else's clone?"