When fighting Link, you need to remember he has more than a few projectiles and will spam them when given the chance. That being said, you need to be prepared to shield arrows, bombs, and boomarangs at will while approaching. If you're just standing while blocking his projectiles, you're getting nothing done from a far away distance. Other than that, spinshotting also works as well as the homing attack while he's spamming. Try not to get too predictable with the homing attack though.
You need to get better at punishing whiffed attacks by either grabbing or using a strong attack that sets up into a nice combo. (0:30)
Try not to waste your smashes when Link is at low percentages. The knockback is stronger from smashes, but combos can easily rack up more damage and could pressure people. (0:40)
Another punishable moment (0:50)
If you wanna follow up with a Spin Charge, I find it useful to hit them once, jump to hit them again, then follow up with an up-air or fair depending how heavy the character is. (1:00)
Links know Sonics like to use their up-B combo. Try to be one step ahead and wait for the link to use dair so you can use bair or fair. (1:16)
Nice! (1:31)
And sweet ending, btw. I also like your use of the dash attack. Next time try some fakeouts and ASC fakes and attacks.