You should definitely use more uair, especially when coming from below, out of dthrow, when you try dair -> knee but the knee won't be high enough. You should also really work on your edgeguarding of Samus. When Samus is bombjumping, there isn't a whole lot you can do, but the most effective thing would be trying to uair after he jumps off the bomb, just be careful not to get your jump stolen with the leftover bomb, spacing, experience, and prediction are the keys to doing that.
If you don't want to go out after him and instead pursue a safer alternative if you know he's going to have to come low and upB or grapple, hang on the edge and edgehop in place (to keep your invulnerability) and when he starts to grapple or upB, drop down, jump back and bair towards him, it's very effective.
I'd suggest to not use so many dsmashes, Samus will very rarely be in a situation to be hit by it, fsmashing when you know what he's going to do when coming on the edge (either from edgehopping, rolling, etc.) is safer and will hit more often.
Go for more grabs, you can either try shieldgrabbing more or using effective dashdancing to get him into it. Once you do, dthrow and try to follow with a knee or uair, uair is safer, but know that Samus will get out of lag before you get to her, so there are plenty of mindgames with that (make her jump and then punish, if she sex kicks you can regrab after she is in landing lag) but just try to play it more safely.
When Samus is on a platform above you, make sure to use uairs and not dairs as you were.
Avoid dash attacking so much, the nair is a much better approach.
Also, if it'll help, here are some matches of my Samus vs my friend's CF. Note that even though they're tournament, they're not entirely serious because we hate playing eachother now (we've played eachother multiple times each week for years). Also, he hadn't really started using the bair for edgeguarding much, so unfortunately you can't see that here. The main things you should pay attention to is how he uses the dash dance, what he does on platforms (both when he's on them and when I'm on them), and what he does from throws.
Yeah, sorry for so many, but there's a lot of variety, hopefully they'll be fun to watch, and both of you can learn some new things.
Pokemon Stadium - Falcon wins
Final Destination - Falcon wins
Final Destination - Samus wins
Yoshi's Story - Samus wins
Corneria - Falcon wins (******** match to watch though)
Dreamland 64 - Samus wins
Final Destination - Falcon wins
Dreamland 64 - Samus wins
So yeah, hope this post was useful.
