@ Afrayail: Thanks nice to hear. Please send me a pm of any questions you have about Toonlink/pika teams. I'll be quick to respond.
@ forever zero: yes, just press the grab button earlier if you are rolling through the opponent most of the time. As for the grab OoS, i think what you are experiencing isa defensive opponent or an opponent with a massive beatstick (ike's sword, Dk... etc...).
The entire goal of an OoS grab, is like reversing the momentum in a fight--they hit your shield and you grab them out of the attack afterwards and stopping their combo/assault. So for an effective OoS grab, some situations must be set up already:
1) YOU are standing still and the opponent RUSHES at you with either an aerial or a dash attack or weaker attack, hitting your shield and (although you slide back from the attack, in this situation, your opponent also will skid with you most likely--that's how the OoS grab will land)
2) Your opponent is standing still and YOU RUSH towards them by walking or dashing towards them. In this scenario, even IF some like Ike tries f-tilt you from staning position, when you block the attack by pressing the shield button as you are dashing and about to reach then, your foward momentum from the dash keep you closer to your opponent whenever the attack lands (you skid backwards a lot less because you still have some foward momentum) and the OoS grab will better land.
3) If only skidding is the problem (assuming you ARE spaced correctly within range of grabbing the opponent ), then powershielding may be an option. It's a lot easier to powershield in brawl than it is in melee. If you powershield ANYTHING, you don't skid AT ALL from an opponents physical attack, so you'll be in range for the OoS grab.
The OoS grab strategy falls apart whenever you are up against a retreating, or very defensive opponent (passive Marth f-air barrage for example), since the range for the successful grab is very tight and one skid will put you outside the range. Try to do OoS grabs only when you are being attacked agressively, or rushing aggressively with a shield. In either case, a shield is swiftly colliding with an attack for a succesful follow-up sheild-grab.