Hi nopiro, welcome to the WK community!
I’ll give my input, although I’m not that much more experienced anyway.
This is the one that needs some more work: I agree with d-hermit’s advice, the first thing you have to keep in mind are the review times, especially the first ones. Doing WK at least twice is a good idea (morning and evening), doing it three times a day (morning, lunch, evening) is perfect.
@cehrlich’s advice is also great. Timing lessons is very important.
Seems good to me, timing is less important for grammar. But it’s good that you are following a structured and well organized grammar.
It sure helps. But I haven’t read it so I can’t say. Since a lot of BunPro’s points point to Minna No Nihongo look them up after you study them on Bunpro.
I guess the experience varies, and as others said, without some grammar foundation it’s not really useful, but after a (really short time) watching and listening to japanese movies/anime does help (a lot, vocabulary is much easier for me because of that!). Still it’s not work. Do enjoy it too 
I don’t think you’ll need RTK. I tried it before WK (only 200 kanji). It’s an alternative so focus on just one. Writing is for me an optional long term goal so I’m not the best to give advice about that. But right now I want to learn Japanese, writing Kanji can wait till after I learn how to read stuff. I do use the “stroke order userscipt” to write the new kanji (I’ve written all kanji/vocab + readings + meaning) but I’m not worried about it that much. If I can’t remember the strokes, I guess them. Unless you want to impress someone with your writing, can’t that wait?
When you see that you can do this amount of work without burning up (trust me, it will get much more difficult than what it is at lv 3), you could focus a little bit more on vocabulary. Either Torii or Anki 4K/6K.
Finally, if you keep that program, I’ll be damned if you can’t pass N5…I think you can easily aim for N4. (Maybe N3 if you never slack off)
Good luck with your Japanese studies and your animated series. (I thought about Radiant when I read you are from France) Tell us the name if/when it becomes real!