Interesting yeah I noticed your tag, I thought most people liked Smashville. How about FD, Yoshis and Battlefield then?
And yes we both have pretty bad smash habits. For me I don't think it's because I panic, I just don't get it punished often probably due to wifi as you said or no one attempts punishing it so I fall into the bad habit of doing it too much.
Also sometimes my logic is go ahead and stale your smash attacks (even if they are great for kills) because I'll get the edgeguard anyway. But I usually never do lol so yeah, it's a dumb idea.
However, MK's fsmash is pretty safe because it has very little cool down and a huge hitbox. It can be punished but it's not easy, even offline, you have to be extremely precise or already in a great position to do so.
And yes I have a bad habit of sitting in shield too much. But it's usually when it's laggy because I can't move like how I want if there's enough lag. I try to be more mobile but those matches towards the middle of our games...I don't know what that was about lol...it was like a slideshow.