If you feel like you need to take a break from forward progress, then I say go for it. Reviewing what you’ve written may help you with your forward process if you need it.
If you take a break now, that doesn’t mean you won’t return to those revised chapters and revise them again, even if it’s a small revision.
If you change them now, you don’t have as much content to go through compared to if you changed them later theoretically speaking. Depends how much bigger the finished project will be compared to how big the project is in its current form.
I will say you don’t need to make it perfect when you first change them to gender swappable. That’s what beta testers are for and people who are interested will no doubt point out pronoun bugs in the code for you.
Yes, do it.
The greatest thing about Dragon Age Origins and Dragon Age 2 was the fact that I could go talk to my party members. Especially in Origins I could talk to them on and on and whenever I wanted to.
Speaking from my personal preference, I’d prefer if I could hang out with the NPCs but not at the expense of losing out on the opportunity to hang out with other NPCs. This means you can have all hangouts happen linearly (but still with the option to opt out by the MC) without the MC having to make a decision between hanging out with Bob or Ann on Tuesday night OR all the hangouts can happen but at different times depending on who you hang out with first.
I don’t like the formula where you’re given a day off but have to choose between hanging out with an NPC, building your skills, managing your resources, or all of the above.
Audiences in the wider market (Steam, Google Store, etc.) have grown to prefer the all important word count over replayability.
This was talked about, somewhat, in another discussion. I’ll link it; maybe it might give you some insight since I myself have no done this.
Generally I prefer ‘less is more’ and like @Gower pointed out… there can be varying branches within those four plot endings.
My current approach is I do these as I go or as I think of them even if I haven’t narratively written the part where they occur yet since I like to write in consecutive order.
Hope this helps. Good luck! 