If grooming a teenager into trusting you, so that you can fuck them, and making yourself feel better for the things you've already done to them, aren't "bad reasons", then I guess that's just how you see things.
An ulterior motive is any motive that isn't revealed. Any unrevealed reason more than simply wanting to help a person when you're helping them is an ulterior motive by definition.
Also Yumi has likely crushed on Sensei since before the start, and there's plenty of inferences. It's also been revealed she masturbates to him:
The main reason Nodoka did that to Yumi was
to cuck her. Hence why she made sure not to give Yumi the option of blowing Sensei. Nodoka believed Yumi would have taken that third option, and as Nodoka said, she wanted Yumi to have nothing.
Sensei also knew Noriko was there and still facefucked another girl (Ami) in front of her, knowing Noriko wouldn't like it. He definitely chose to do this instead of stopping her. He did do similar to Noriko with Niki back in the day, but back then, yeah he didn't know she was actually there. I'm also thinking a similar scenario happened with Maya, but that needs more intel.
It's not grooming to help them, the other cases yeah, but there was no apparent grooming or even sex based motive behind the specific actions I mentioned. The majority of his actions, yes, they would have a sex based motive and would be grooming because they are working toward his goal of fucking them and blatantly so for anyone other than the girls he's trying not to broadcast this motive to.
However, when even he questions why he does something and he's
helping a girl who isn't going to get any closer to opening her legs for him by being helped finding a job or
a girl who isn't going to open her legs because he was there as emotional support when she got rejected or was depressed, then either he's insane by definition in that he's trying the same thing over and over expecting a different result or he's not expecting what he knows he's not getting from these actions.
An ulterior motive also has to be a result expected by the person who has it other than the outcome they are helping to achieve, such as
finding Yumi a job, that in itself would be disqualified as an ulterior motive because that is the outcome both of the two characters involved are expecting. For this case, he would have to be expecting Yumi or Rin to give him something in return for both of the above inline spoilered cases that is not
Yumi getting a job and Rin getting through her emotional rough patch, but he shows no signs he was doing them expecting anything in return for those specific actions. Throughout the story, the majority of his actions do have one very specific expected result, sex with a girl, and that would indeed be an ulterior motive but that is seemingly absent in both of the above cases.
As far as Nodoka, not sure how it would be considered cucking to
suck a guy off in front of a girl who constantly shows hostility toward the guy being sucked off. If she was actually showing her true feelings openly, because tsundere plus what you revealed above, and Nodoka knew about them, then yeah, but she
shows the opposite almost full time and the few times she doesn't she's showing herself to be neutral at best. I could see it as Nodoka making a move on a guy who is clearly open to her and apparently not taken by Yumi, however, and I could see this as the
sexual harassment it is without even considering it
cucking Yumi.
Again with Noriko,
Ami wasn't giving him a choice. Saying no to
a girl like Ami is possibly a death sentence later plus an immediate forced...well, I'm not even sure it would have stopped where it did if he had said no, in fact,
she probably would have taken the opportunity to go further if she had to take the lead because he refused her advances. Taking an action, even knowing someone is there, without a choice isn't cucking. Ami, however, would be
cucking Noriko if she knew Noriko was there, but her presence
was only revealed part way into the action and both of the others were unaware up to that point.
You more or less just said what Nodoka has been saying, just with an added caveat that he has "good in him" which I dont recall Nodoka ever saying he didn't, so I'm not sure why you'd say she's wrong.
Nodoka's whole thing is wanting the real Sensei:
There's a reason Sensei is secretly envious of her, while considering her an ideal version of himself:
Sensei is similar to a Nodoka that is cowardly and delusional in a way.
Hence, why he's using Nodoka as an outlet for the feelings he hides from everyone else:
Nodoka is someone just like him:
Honestly, I find it a little hilarious how Nodoka seems to be demonized when Sensei could be seen as a much worse, more experienced, and much more cowardly version of her, except, you know, twice her age with a cock. Sensei makes her look good in comparison imo.
They both get demonized for their respective actions and both rightfully so. It doesn't really matter which one is worse, both would be jailed for what they have done in real life, they are both the morally worst characters in the game, yes, even Otoha beats them and she's a known willing cheater who does nothing to hold up her end of a relationship and treats her lovers like they don't even exist, like complete garbage, or like everything is their fault, possibly all of the above combined. You don't really need a ranking once two or more people go into criminal territory, they both get the same thing out of it when caught. Yes, Nodoka is morally better than Sensei, but that doesn't make her good.
