Do you realise how silly that is? How many stories, games, films, TV shows, etc, do you know of that show and tell you every single thing the characters get up to when not on screen? Because I'll tell you right now, they don't do that. You might get some expositional dialogue about off-screen stuff, but it's not a necessity nor a guarantee in any story to be spoon-fed this kind of info as you seem to think should happen. You only assume they don't spend any time together because you want that to be the case since that fits into your narrative and you take any lack of confirmaition as proof of your narrative when it isn't. We don't know for sure in the other direction either, but at least we're not denying the truth of their relationship situation and the feelings they have for each other like you are, so us assuming they are spending some time together off-screen is at least more reality-based than your view.
Eh, no, because their relationship is not "poor" on the throuple, it's in a better state with him, and if they spend time together unseen on that, that's a good thing. There you go again with the alternate reality malarkey.
In Ep 6 it was relevant to show Maya's insecurities about being with a guy and being part of this new, unconventional relationship. In Ep 8 it was relevant to show them discussing some things and clearing the air a bit. After that, there hasn't been, imo, anything we needed to see of them when alone together that's relevant to the throuple overall or the MC. If there is, we would see it, but a scene with them that's just them hanging out, being intimate, etc, that doesn't relate back to the relationship overall is not necessary.
It's not an "easy route" when someone's Dad is literally threatening their entire future over their relationship and they're having a hard time finding a way out of the predicament. It's an apparently serious threat and their caution is warranted albeit difficult to deal with. Not to mention the fact that Maya's probably worried Patrick could cut her off from seeing her Mom and she wouldn't want that and he might even take it out on Derek too. There's a lot for stake for her here and they both know it, that's why it's so difficult for them.
There is a saying, "love conquers all", but it can still be a difficult road to get there. It's not as easy as saying, "I choose you", in a relationship that faces some adversity and it's all flowers and rainbows after that. At the end of the road, sure, love may conquer and things are alright, but it's not always an easy road to travel and bumps can appear that you either overcome or trip you up.
Right now, Maya's caught in a position where she potentially has a lot to lose - Josy, college, inheriting massive debt, access to her dying Mom - because of her Dad's threat, and as much as she loves Josy, which she does, it's hard for her see a way out of all this where things work out and she doesn't lose all this. That's perfectly understandable to feel like, as much you love someone, you don't want to lose other things that are also important to you. That's what makes it so difficult for her to just choose Josy and why she can't choose the opposite because both choices hurt her. Josy, meanwhile, also knows what's at stake for Maya and wouldn't want to see someone she loves, which she does, get hurt or otherwise face serious issues over this. She's caught between wanting to be with Maya, not wanting to hurt Maya, but also wanting a less stressful relationship. That's why she "doesn't know" what she'll do if things gor wrong at the dinner because she's conflicted between all these things.
So Patrick and his threat IS the wedge that's causing issues, that really can't be denied even though you are trying desperately to say that it isn't because you can't handle the truth of the situation and want to live in your own version of the narrative.