Xigfrid, honestly this is so so good though.
I remember comparing the newer 1/60 VF-1 toys when i got them right next to the YF-19 (my fave) and thinking the VF-1 was so small. Then with the first round of the VF-5000 print comparing to the VF-1 and thinking, 'Oh no this is so so small' But honestly I think your scale is spot on. Plus your other models have been larger even as a 1/60 scale. Don't fret!
The only few finesse things i can see/think of would be... (that i'm sure you're aware of and have been mentioned all ready really):
Nose - yeah if there is a way to make it smaller/skinnier that would be amazing. But understand you have a lot of inner working stuff going on. So maybe it's even just the shape that could change slightly... just a bit more thinner under the cockpit area. Also, and if you could find a compromise for the size of the end of the nose so it's a would appear a bit smaller in robot mode that would be great.
Shoulders - Not too sure how the join to the body works and how much space you have to play... But one way to reduce the gap could be turning it into a sliding and lock mechanism on that top bar so the shoulder screw is actually closer to the body? I don't know maybe there is an easier way as you've already mentioned everything is so fiddly. As someone else mentioned maybe it's making the wings bigger to cover it up... I feel like just making the shoulder joint closer to the body will just help.
Top Air intakes - By top air intakes i'm talking about that whole tail fin section. I think in robot mode the need to protrude up a little more. It's such a loverly detail that comes with most VF's that normally from their 'backpack' part. You gotta show them off. Also is there a way you could get rid of the plastic pin in that part? Is it for stability in Plane mode? Just wondering if there is another way to keep things together while flattening out that area.
Legs - If they could go a bit bulkier, that may match the artwork a little more. But that really is a personal aesthetic thing at this stage. I just prefer the bulkier valk styles like the YF-19 compared to the VF-25 or even the VF-31. But i do feel compared to the bulk of the arms, the legs feel a little skinnier comparatively.
Heat shield - Honestly don't know the best way to fix this as it would probably impact the wing size too much... but if you could think of a way to add just a bit more height to the heat shield area just so it can be a bit more in line with that next 'module' of the canopy.
Want a better word that 'module' Hopefully the pic below helps a bit more with explaining most of the above.
But honestly man, it's great! With the feedback, you'd know what you want to do with it really. And honestly i'd pick this up in a heartbeat as is! Any improvement from here is pure polish!
Chat soon man.