Slight:

我比較好奇的是，如果我跳出界外，把球撥回來，然後自己又回到界內拿球，那樣是否違例？

如果是救球, 也就是說球已經 lose control, 那是 ok 的, 但是這點其實很多不清楚規則的裁判也會判錯,
如果是球員自己運球過人的時候這樣耍, 則是違例.

24. Player A1 saves a loose ball from going out-of-bounds by batting the ball back onto the playing court. May Player A1 be the first to touch the ball when he returns onto the court?

Yes. The batting of the ball does not constitute player control, therefore Player A1 may be the first to touch the ball.
RULE 10 - SECTION II - b

252. Team A has just lost control of the ball and it is in the air over the boundary line (never having touched out-of-bounds). Player A1 leaps from the playing court, bats the ball back into play and he then lands out-of bounds. What is the ruling?

This is a legal play by Player A1. The ball is not out-of-bounds until it touches someone or something that is out-of-bounds. On this play, Player A1 may also be the first to touch the ball once he touches inbounds with one foot and is not touching out-of-bounds. If Player A1 threw the ball back inbounds, he is not allowed to be the first player to touch the ball.
RULE 8 - SECTION I
RULE 10 - SECTION XIII - g

b. A player in control of a dribble who steps on or outside a boundary line, even though not touching the ball while on or outside that boundary line, shall not be allowed to return inbounds and continue his dribble. He may not even be the first player to touch the ball after he has re-established a position inbounds.