More or less, this is not a bad way to think about it - with a few caveats. The first is that moves in Tekken have tracking. What this means in practice is that they don't always function in a linear manner on a 2D plane and can instead hit you when you sidestep to one or both sides. Part of the knowledge requirement in Tekken is understanding which moves will track to which side (and, hence, you should sidestep in the opposite direction to make them whiff). Furthermore, some characters are very linear and thus susceptible to sidestepping while others have fantastic tracking.
There are, in fact, top tier players who barely sidestep at all and rely almost entirely on backwards and forwards movement. However, they are able to do this because they are very proficient when it comes to Tekken's particular brand of esoteric movement mechanics. In Tekken, simply tapping backwards or forwards, or walking, is extremely slow. On the other hand, you are able to cancel out of forward and backdashes by inputting either a crouch (d/b) or a sidestep. Proper movement in Tekken involves rapidly canceling from a backdash to a crouch to another backdash, etc (inputted as b, b, d/b, N, b, d/b, N). When executed properly, you not only move about 3 times as fast as a normal backdash but you are also blocking throughout the entire animation.
Also, ignore 10 hit combos. They are simply an odd legacy feature still included in the movelists for some reason. They aren't actually real combos and can be blocked, parried or even launched by better players. If you want to know whether your inputs are actually a combo, set the training dummy's first action to 'stand' and the second action to 'guard all' and watch to see if they block your string.