I can agree with tilts killing, but d-smash for catching a roll is still a read you need. Hard or not.
I'm calling roy's combo potential not that useful. Not whole smash 4.
I can disagree there. While marth does more damage, it's more on the tippers. Lucina doesn't need to rely on tippers and can go straight rushdown.
Edgeguarding isn't easy, but it's not too hard actually. Character with bad recovery like dr.mario and little mac is pretty easy to edgeguard. Roy is also falling down in that category.
While Lucina's recovery is bit predictable, it's not easy to edgeguard her up b considering it's super fast back on stage. Roy's one is kinda slow and it is still easy to gimp it. And doesn't side b help bit? It works on marth atleast i know.
I don't think lucina's KO power is better than roy as you said. Roy is designed bit more powerhouse than speedy type.
I think up b, fair offstage and up throw can also kill too for Lucina.
She have better frame data than roy which is important. Faster aerials and longer range.
That makes her move much more reliable than roy as for killing and edgeguarding.
So you are saying Roy relying on more on hard reads? That's not a good thing. I don't think roy is fully rely on hard reads like ganondorf, but he need atleast some reads to get the kill. And online doesn't matter where it can be lag so ruin mess up your moves. Offline matters most.
I think lucina is 2nd/3rd worst and roy is worst FE in sm4sh.
It can be argured, but i'll hold this opinion still.