I have gotten some fraudulent wins that way, and I honestly wouldn't mind if they did increase that time if they left everything else untouched. Otherwise, I don't feel like she's a character that deserves nerfs. Though a great character, her huge hitbox and extremely light weight balance out some of her more powerful qualities. Along with a lack of killing movies, I think she's relatively fair, though customs is another story. I don't even think customless Rosalina is that good.
I think I'd heavily reduce the lag on her luma shot return and not let luma act while returning to her unless she calls him manually. I don't really mind if it can act out of light hitstun like jabs or whatever, gotta give the mashers something, but not being able to chase her into the air because luma's return path will intercept you is at least the 3rd most obnoxious thing ever.
Nice, he switched to Sheik after going down 0-2. The scumbag tech.
I don't think the hits with Luma after Rosalina gets hit are necessarily fraudulent. Luma can't act after Rosalina gets hit until Rosalina can act herself, and if you didn't hit Luma away along with Rosalina and are still standing in the same spot after her hitstun is done, you should know the matchup enough to know that you are vulnerable to getting hit when Rosalina is out of hitstun. If you hit Rosalina and can actually follow up with a combo before her hitstun is finished, Luma isn't going to stop you from doing so. If not, you may get hit by a Luma u-air the same way you might get hit by a fast n-air from many other characters. If you tried to go in on Luigi after hitting him and took a n-air to the face, you wouldn't call that Luigi getting a free hit when he should be getting hit. You chased too hard and got punished for it.
If you go for a grab on someone that is able to throw out a jab right before your grab, the grab will break immediately as you get hit by the jab. If you try to grab Rosalina while Luma is tethered and she has time to start an attack before your grab, Luma may hit you out of of the grab in the same way since the attack already started. The only thing Luma possibly saves Rosa from more so than other characters when getting grabbed is when they try to pummel after the grab with a character whose pummel doesn't also hit Luma. If you grab and throw Rosalina without idling around for a stupid amount of time holding her, Luma can't do shit to you and a lot of times will end up dying from the knockback of Rosalina getting thrown. 99% of the time in the case of Mario's back throw.
Luma shot return is already a lot faster than it was in the 3DS in the beginning, so when you manually call Luma back, Luma has to be really far away to actually be able to do an attack while returning, and if you try to call Luma back when you're too close to the opponent, Rosa should be easily punished for it. The times that Luma usually is able to attack while returning to Rosalina is only when Luma is still actually tethered to Rosalina and Rosalina is hit away from it. Then Luma starts to come back after a set amount of time in a few seconds automatically or starts to come back immediately if Rosalina does an attack. If you're already too far away from Luma to get hit by Rosa attacking to bring it back earlier, then Rosa has to wait for that set amount of time before it starts coming back itself and then do the attack to be able to reach you. I feel like pretty much all of the "janky", "free" hits that Luma gets on people are entirely avoidable with matchup knowledge and understanding how Luma works.
Learn how Luma's dirty asshole tricks work and what you need to do to avoid them before just saying she needs teh nerfs. Rosalina already got her jab finisher nerfed this patch ;_;