The last chapter actually made me like Floch a little more, but generally, I considered him to be worse than Gabi. Mostly, because he really goes out of his way to be an asshole. There was no reason for him to bomb civillian homes during the Assault on Liberio and it gained them nothing to murder those civillians. I understand why they attacked Liberio in general and why they were ready to accept civillian casualties, but Floch really went out of his way to punish Eldians - who are the victims and universally hated - just because other Eldians were transformed into Titans and sent to roam Paradis.
Next, he had his new followers brutally beat up Shadis and again, had no reason to do so. The general opinion was already shifting in favor of the Yeagerists, so I don't see why nearly killing Shadis was some way of proving themselves.
He also attempted to kill Levi while he was severley wounded, despite Levi being humanity's strongest soldier and being in no shape to fight. He could have easily captured Levi so that he could be used as an ally in some future situation (like the one Shiganshina's currently in, lol).
I get that he is doing all this for his country and that he is trying to put Paradis in a situation of strenght, but while doing so, he is too determined to be an asshole for me to like him. However, I respect him for fighting Pieck on his own.
I full-heartedly understand why people might hate Gabi, although I personally don't. Most of this seems to be bias because she killed fan-favorite characters Sasha and Eren, although I doubt that Eren is dead tbh. Her motivation for both kills is understandable though since they clearly are/were her enemies.
Other than that, I see her as a victim of systematic indoctrination and think that you summed it up pretty well with
"She is trained to believe Paradis Eldians are not humans who cannot be reasoned, bargained or be negotiated with. Gabi served Marley in hopes that by doing so would elevate her family's unjust hardship. Eren's Raid on Liberio only solidified her bias. No one was there to mitigate her bias, no one could dare to fix her bias. She is trained to kill 'devils' and she did when those 'devils' invaded her homeland. Once in captivity she did what she is trained to do, do whatever she can do to resist and she did that. From Marley-Eldians (including Gabi) perspective Eren and Survey Corps are the invaders here"
So no, I definitely do not think that Gabi is worse than Floch. I like almost all characters in some way except Floch :/
Regarding Shadis, I came to conclusion that Shadis sacrificed himself by provoking his cadets into beating him to spare them from being persecuted by Jaegerists led by Floch. Never knew Shadis had that mindset in him.