Straight-in or circling app are terms used only for FINAL app. Before that you have INITIAL and INTERMEDIATE app or radar vectors. Straight-in app doesn't have anything with landing. After FINAL app you can execute landing or missed app.
On some airports you can have offset final app (Tokyo Haneda LDA 22 app or Nice 22) with 70 degrees difference between FINAL track and RWY track but you still perform straight-in app if you enter FINAL segment within +/-30.
And there are no different limits for different aircraft categories.