I agree on the voice control sucking, but that can be fixed by singing. Keep practising singing on-pitch in a comfortable range (with no straining) to get the motor skills improved in the throat section and get your relative pitch perception as good as it can be.
Work on your breath. You can use breathing for effect (as Beyonce would do it), but you need to make sure you have to ability to hold back (the high note suggests you aren't completely oblivios to that concept, but keep working on Ãt). Maybe singing half a verse of this song in one breath.
Play with your voice. Make dark tones, bright tones, solemn tones and wacky tones. Find out which ones you like and apply them in singing (eventually becoming your style).
The high sustained notes (F4) in the last chorus (after changing the key) sound really good to me and it sounds like you got a boost of confidence hitting those, so you got into the song a bit more and raised the overall performance. Don't be afraid to sound like shit or it'll make you sound more like it. (In performance, not practice. In various Idols, Voice, Popstars and X-factor T-shows we've heard these people who immerse themselves so deeply in the music even when they practise, that they've never heard how awful they sound.)
Although the high notes don't sound strained, you probably need to retool your approach if they are - even if it sounds good.