Make sure when you are using fair onstage you autocancel it.
Save your second jump when recovering. It makes recovering a lot easier for Bowser in general. The only time you should use your second jump early is when you momentum cancel with a fair and are still going to be sent past the blast line.
Learn to tech
I noticed you got one near the end of the second match, but it's handy to be able to do it consistently
Against characters like Samus whose aerials and zair have very little, if any, landing lag, it's almost always the better option to Fortress OoS. It's just much safer and much more reliable in the Samus matchup. If you are approaching an airbourne Samus and powershield a missile/zair/aerial though, feel free to get that grab in
I would normally comment on your lack of klaw usage, but since this against a character who is nearly impossible to approach in the air (at least as Bowser), I'll forgive you. I just hope you are using klaw more against other characters who aren't so anti-air
You are definitely a nice Bowser. I hope you keep representing Bowser players over at HOBO