^Trying to find a secondary and seeing which gets the best results I'm guessing. Anyway your Marth needs a lot of work. Really it boils down to knowing the character but seeing as you have 6 different potential secondaries I won't rat on your *** about that one.
I wasn't really impressed. Main thing to note is your spacing and f-smash. Really need to work on spacing b/c you are whiffing a lot of times esp. with dair which is usually the hardest thing to learn to space properly. Also I know ness has deceiving range on his f-air and dash attack but f-smash is not the move with the longest range and there are many ways to counter if ness chooses to do them.
I'm guessing it might be your Olimar senses kicking in b/c f-smash would probably block those approaches. However, for Marth you have a lot of options. You can shieldbreaker/d-tilt and hopefully hit him before he can get in with the f-air but really you use them as poke moves telling him to back off. You can counter. At high% you can use Marth's upB but this is a high risk high reward option. There are other options that I won't get into.
Also work on your gimping. You tried to gimp with dair against Ness in the first vid and didnt exactly do what you intended but got the job done. I don't want to get into too many specifics, because I believe you should learn Marth a bit more before asking for critique, so I'll end it here. But I did like the unique use of some of his moves that you usually don't see. The fair > jab 2x (first vid) was an interesting string of attacks and the aerial DB > dair (second vid) was also eye catching. I think you should continue to pursue Marth as it will be interesting what type of new style you could add.
