Yeah I would suggest you put up Brawls vs humans, I watchedt hat video and I am like...okay, so he can beat up a bunch of "lv 9" CPUs, but I know that even a mediocre Meta Knight for example would not fall for the same trick so many times, in this case dair spikes.
what I can tell you to improve on though, is that you shouldn't use smash attacks when the enemy is at that low of a %age, yes Ike has the godpower but that won't get you anywhere if it doesn't connect, and they usually leave a lot of room for punishment, not to mention his Smashes won't really kill until after 50% fully charged. When you were fighting that D3 I noticed somewhere in there you let him come back to the stage, you know if you used your d-tilt it has the same spiking property as Dair and may sometimes serve as a safer method of edgecamping? Try to use Nair a little bit more for short-hopped approaches, it hits all around him and compared to the other aerials approaches has no landing lag. I also saw that there was no grabgame, I know Ike's grab is not impressive but can lead to combos, for example the infamous D-throw to Aether/Uair can rake up some decrnt damage, as well as a F/B-throw over the edge to a charged Smash, some opponents will try to recover back up to the stage but can sometimes fall into the smash which leads to a kill. Lastly if for whatever reason you can't do SHAA (Short-Hopped Aerial Approaches) try quickdraws, but be careful with this, if you miss there is ending lag where that would have deadly results, if you come up short on the Quickdraw you can follow up with a Grand-Viper (F-tilt) or the simple AAA combo, the beauty of quickdraw is that if you don't do the initial strike, is that tehre is very little landing lag which can throw off an opponent.
Maybe some other people can lend you advice but that's my two cents.
