This would need a very high nanite factory level as well as robot factory level maybe nanite of 5 and robot of 15 or so.
this decreases building time of ships, defenses, and buildinga by 1 minute per level starting at around 10mil metal, 5 mil crystal and 1 mil deut.

Level 5 nanite factory is not high at all.

ok more like 8?

nice idea.. however if this is applied after the nanite bonus instant rips would be easily within reach of any players around my size and above.

if it is applied before the nanite bonus... then the bonus is:
60s/2^5 = 60/32 ~ 2s
60s/2^8 = 60/256 ~ 0.25s
60s/2^10 = 60/1024 ~ 0.06s
per level of this building.

obviously providing us instant rips that easily is ridiculous, so if this were to make it through, the level of nanite is redundant.

I believe this is either a gamebreaking or pointless addition.
to make it work, change the 1 minute per level to something of a different form and check the math.
for the record I enjoy the benefits of a level 10 nanite factory, and I'm sure larger players have higher though.
at a minimum a 500x time reduction from nanite (level 9) should be taken into account, this is achievable for most players if they stockpile correctly.

There is already everything in place for faster ship builds and other builds....just get higher nanos/shipyards and robos ...sorted.