He whistles, the arrow gets faster and at the same time catches fire.
wrong. Its obvious he did it on purpose. The arrow was already moving str8 for tazerface.. There was no need for him to whistle a second time. And when he does whitsle , , it simply catches on fire. And as it turns out he wasnt even aiming for him. It was for whatever combustible thing was behind him, hence the explosion. Logic says he wanted it to have a flame to cause the explosion. Unless you are implying yondu missed and the it just happened to catch fire, and just happened to do it at the perfect time to cause the explosion... But youd have a hard time proving that as we havent seen yondu miss. not to mention if he simply missed taserface, why would he let the arrow keep going? And not just turn it 180 on a dime like he always does? He clearly ment to hit the fuel tank or whatever blew up. He clearly wanted a flame for it..
Not to mention rockets immediate reaction to blowing up the ship calling yondu a maniac..implying yondu did it on purpose.
Also not to mention the way the scene is cut and the obvious different kinda whistle yondu did before it cuts to it catching flames. Its like a stutter whistle which was vastly different to what he was doing before. I think all signs point to it not catching fire from random speed, but purposely done. go to 3:23