While I can't provide technical info, I can provide insight. When I fight Ike's I use a mixup between Bomb Guarding from above (jumping / retreating or platforms if possible) and actual head on fighting him off. Basically if you knock him away from the stage and he's trying to recover I look at it as two primary options.
Run out and try to attack him. If possible knock him back before his Aether can initiate or is close enough to practically use it. Once in that zone, edgehog. You'll get the timing down with some practice (have a friend help, it could work) so that you can hug/pull up and not get hit by it by use of your invincibility frames. While you won't kill him and he will grab the ledge, you should be recovered enough to be ready to strike up close or use a retreating projectile.
Take the free damage and let him live. A boomer, arrow or bomb well placed is nice free damage, and in some cases pushes them back down to cause more of a mixup on them. Ike's are slow so keeping your distance is fairly safe and if you can angle your projectiles from above or a platform as he's trying to recover, you really have nothing to worry about.
As for on land, if you see it coming and can range it, I once again recommend doing that. Its not gonna get you any KOs but it will rack up damage and help reset the counters on your other moves knockback/damage ratios if you just got done with some spam.
Spiking it from above or below with uAir and dAir are both potential ideas, but the timing is a bit strict and can result in a double hit or a miss on your part if you're not careful. If you're feeling lucky or confident or just have a lot of practice this works too. Not sure exactly what the knockback was like on any of those situations, its been awhile.
Perhaps once you see it starting run past/quick dodge and prepare your bAir spam. When Ike's finishing the animation if you can get yourself setup you've got a pretty much guaranteed bAir combo ready to be unleashed. This of course can be mixed up with anything else, but bAir is my usual choice of action.