Have to agree with Bob on this one. When learning we sometimes tend to make certain shots the same way, maybe because we find we have more success with that method, regardless of the underlying reason. But aside from certain specialty shots, you really need to learn to make shots with whatever english is necessary for position.
The shot you are describing is a pretty difficult shot, especially over the length of the table, 80 - 90 degree cut. I doubt anyone in the world could make that shot more than 80% of the time, which is really a good benchmark to decide whether to shoot the shot or pick another option (bank, safe, etc.). Doesn't hurt to practice them occasionally, but don't get too hung up on it.
As for the inside english, it tends to deflect thinner and for some people they have better success since they are aiming a little thick on the shot and the inside helps them achieve a thinner hit. Center ball can be used as well as outside, it all depends on where you want the cue ball to go next. But since the shot is so difficult, if you feel comfortable with inside, or high inside, then use that as your go to shot if you are in a situation where you have to make that shot.
Scott