I ENJOYED it. But as it has been said,
But....honestly I liked the idea of it. I hope everyone else would instead of just saying that everything was wrong, they would comment on what to fix so that we can have a really good version of this. Noobs are attracted to combo videos and instructional videos. It's what they absorb from the most. Now having a PROPER instructional video on marth would be terrific. It highly reduces the noob problem in the sense that they have an IDEA of how to properly play Marth, even if they don't do it as well as they should. But at least they can understand the way Marth's game actually works.
I was actually pretty alright with it up until around 1:40. Granted SOMETIMES it's an alright idea to set up an attack with the first hit of DB, but it's discouraged since it's more of a, I can probably pull it off once or twice maybe if I get lucky but then they'll catch on and punish me for it....kinda thing.
Viet already covered this, but also add a vid of up+b out of shield ON R.O.B.'s Shield. It makes the point of it a lot more clear. But also add a video of up+b out of shield with tap jump off to really get the point across of why it works(the invincibility frames).
For attacking people before they get up, I wouldn't so easily just say to always do it. Always doing something in a situation where it can be punished is bad. Get up attacks present this problem. Any half-way decent timing of a get up attack can punish you for blindly charging in to attack them.
During the ground section, you make it seem a little too much like what you're doing(Exactly as you're doing it like 3 or 4 utilts in a row) generally works in a match. But generally, it's a bad habit that won't work on skilled players. I know that you're just demonstrating the actual use of it, but try demonstrating it with juggling instead. Introduce utilt, usmash, and uair all at once and show their use by alternating between them while juggling someone to their death(make sure to tip).
Good job on dtilt. Might also want to cover a section about how it pokes under shields after one or two, and after shieldbreakers.
For the dash attack, no quarrels. But straight up approaching with a single hit form dancing blade is a bad habit. Marth has much better options to approach with such as dtilt, fair, etc. Dancing blades is nice for STOPPING an approach or punishing a mistake. Not so much for actual approach.
For the love of god make a note not to abuse fsmash because you get horribly punished for it and you need it as a kill move without move deterioration.
Typo in walking sub-comment.
For the throwing section, do not advice to go for a throw to tipper dair unless it's on one of the guaranteed(like wolf I believe at 0%?). It's not generally practical since it's pretty easy to avoid otherwise.
A final note from me(but only for the moment. I haven't finished reviewing things to amend) is to go on about grab releases since Marth has a lot of guaranteed hits from grab releases on certain characters. Look for the thread in the sticky thread that has links to useful threads.
Anyways, I hope other people decide to critique it too so we can actually have a useful guide for noobs. Increasing awareness about Marth might also decrease stupid posts.
I'll finish my critique later.(stopped at 4:53 aerial game)