So do I feed into the camera directly or not?
You could use a wireless camera hop from the recorder your sound recordist is using to your camera, but from the theme of your posts I strongly doubt you'll want to spend the extra for a wireless camera hop.
Thus just get a Timecode box for under three hundred dollars plus a scratch mic on the camera and leave it at that.
https://www.bhphotovideo.com/c/prod...ultrasyncone_ultrasync_one_timecode_sync.html
https://www.bhphotovideo.com/c/product/1372225-REG/tentacle_sync_te1_sync_e_single_set.html
I've remained a voyeur to your many posts so far but this one has just gone too far.
I'm not a sound engineer but I find that advice pretty suspicious. I shoot interviews all the time with my mic going straight into the camera and its perfectly fine. The main issue I would imagine is shooting a feature with a sound person. Budget or not that sounds nuts to me.
First of all who's monitoring the audio and setting levels - the Camera Op? They won't have the mental bandwidth.
A 416 just won't cut it for catching adequate audio in many many many situations and this issue dwarfs your continued worries about 4-2-0 vs 4-2-2 or FS7 vs FS5 or 4K vs HD. You're better off shooting with a DSLR or certainly an older C300 or an F3 and using the extra dough for an audio person and a few wirelesses. You don't need a guy with a nagra, and you really could even get by without a separate recorder, but for gods sake get yourself a guy or gal with a mixer.
I disagree about getting a guy/gal with a mixer, s/he must have a recorder as well. The days of a person only having a mixer are years and years ago in the past.
But otherwise I agree with the bulk of what you are saying. The op could very well get a Sony PMW-F3 / Canon C300 mk1 / Sony FS700 and do perfectly fine, as any "lack of quality" in one of these older professional cameras vs the newest latest professional cameras will be vastly VASTLY overshadowed by the many many other issues the production is looking likely to have. (lighting/cinematography/audio/etc)
Oh and it is not just a case of the camera op not having the mental bandwidth to manage audio properly as well, but he PHYSICALLY can't do both at the same time! He is not a teleporting octopus with multiple arms and able to be at all places at all times. You simply can not boom and operate a camera at the same time.
What is becoming insane is your incessant posting.
Maybe you should stop posting on the internet and actually go shoot something.
The OP said once he has been ten years since he last shot a film?
It would do the OP a *lot* of good if he went out and helped on half a dozen short films (even an awfully badly run student short film! You can learn what not to do, ha), then shot a short film himself, before trying to gamble it all on embarking on making an epic feature film.