Mass doesn't match the name at 4.08kt - is something wrong, or just not updated name?

I like the new update.

NP.
Also, a bit of a tip regarding aesthetic values (read: I want shiny gold stuff on my ship!) - titanium nitride is superhard refractory ceramic that also has a nice gold colour.
In general, quite a few ceramics combine interesting colouration with desirable anti-kinetic and anti-flash properties and can be worth looking into if you aim for stylish, yet practical.

thanks for the advice , i will improve in some point in the future !

A few observations, if you don't mind:
* Your ship still has a single point of failure - single power reactor. Using multiple reactors, spread along the length of the vessel, and some preferably off axis would make the ship much sturdier. Backup RTGs are a nice option too if you also have some low-powered backup weapons or want to use flares despite powerful reactor.
* I consider using RCs on crewed ships cheatish, but if I wanted to use them I would put a whole bunch, offset from axis - maybe two rings of 20? Your single RC is often getting destroyed.
* The ship can turn rapidly enough to kill the crew located in the forward CM - they might be well protected from gunfire, but not inertia. Different crew arangement or less powerful engines might be a good idea.
* More diverse battery might be a good idea. I can usually penetrate single-battery CIWS easier - even if it performs well against one of the missile types I use it tends to be pretty helpless against another.