im really sorry to hear about how your day went excel, if it makes you feel any better ive had some of those too(i had to use GW in singles LOL), i cant do this too indepth as im going out for my birthday soon but heres what i got
dair to grab at low % instead of utilt
always remember that swords > nair, be careful how you use it
stop airdodging after you get grabbed, better yet just stop airdodging into your opponent,i noticed you did this ALOT
midway through the 2nd stock you just became really impatient, this is understandable however if you were having bad day, just try and take things one match at a time from now on
at 2;19 you shouldnt have done a FH dair to punish his recovery,get up attack was probably the only guaranteed hit, or you could have rolled onto the stage and waited for his probable spotdodge and punished him
2:42 no point in trying to dsmash after you just daird into his sheild,avoid dair into marths sheild at all times btw,im surprised that marth didnt use up-b oos to his advantage when you did this
you need to sweetspot the edge more, marth can **** illusion way to easily, it was good that you cancelled your illusions to mindgame him a bit,but your much better off going to the edge
one more thing, you set yourself up to be dtilt locked twice(you escaped the first attempt) because you did a SHL right beside him both times, no need for lasers when your backed up against a corner you need to fight your way out or just escape the situation entirely
the biggest problem i noticed was the airdoging stuff, this NEEDS to be fixed and is definitely the core reason as to why your not having the success you hope for at tourneys