Mix up your shield pressure so marth can't grab you as easily, nothing falco has its 100% grab-proof so try double shines and fadeaway nairs/dairs instead of going Dair shine dair shine more than once in a row.
Dash attack while both of you are on the ground is really risky, if you dont cross over youre screwed, and if you do and you think they're gonna grab, go for the U-tilt to start combos.
Down throw is almost never worth it, especially on yoshi's where up throw can lead to platform combos really easily, use more up throw. At high percents, if you think you can down smash them out of a missed tech, its worth it to try, but at low percents its better to rack up damage than to test the waters on something as simple as teching fox/falcos down throws.
Some of your full hops seemed accidental, especially when you were comboing. If you're full hopping to get away from him, marth is a beast under you and can U-tilt and U-air you all day long. If you double jump and he hits you off the edge youre dead.
Watch your forward smash usage lol, its a great move but you tend to die when you spam it.
On yoshis, its ok to go around and jump when they die, but dont jump as soon as they hit the ground, make sure youre on the ground going pew pew. He managed to up air you once , but if he had kept you on the left platform he could have stringed up tilts into an up smash and ow that hurts.
Im too lazy to time stamp i just wrote this as i was watching your matches.
Work on being unpredictable, that seemed to be why you were getting killed the most.
