Keeping thing quiet with a custom C Beam XL

I'm moving into a house without a garage and need to get a smaller machine. I'm still very much a beginner so I want to keep it as a hobby rather than a second job. For this reason, I want to have it inside, even if it limits what I can do with the machine significantly.

I'm planning to build a modified C Beam XL using parts from my high Z Lead 1010. I'm going to add a 1.5kW water cooled spindle (Huanyang), for that I will probably need to replace my standard Nema 23 steppers with high torque Nema 23s.

It should have a work area of ~350x750x65mm. My primary goals are small wooden trinkets, engraving/cutting out of 3-5mm aluminium sheet and some dragknife work with acrylic. I've used a standard sized C Beam before and I was happy with everything except the build area. I'm trying to stick to the parts I currently have, looking through my list it seems all I need are some 500mm C Beams and some shorter leadscrews

This build is primarily going to live indoors, so soundproofing is really important. I've heard, when designing an enclosure you should:
- Add absorbent material (eg mineral fibre/rockwool)
- Add mass (Mass loaded vinyl/granite slab)
- Seal airgaps
- Avoid windows (I may make the window smaller or remove it completely and rely on cameras)
- Use a water cooled spindle

The sketchup model below gives a rough idea of my design. I will be using rubber gaskets around the door and the cable holes to restrict airflow as required. One thing that I am really struggling with is dust collection. I've seen some people use 3D printed fans on spindles which looks like it might be a quiet way to get some chip evacuation but i'm not sure if this is the best approach.

From what i've seen, most shopvacs (like mine) use the air flowing through for cooling, which could be an issue as I want to keep the case as airtight as possible.I still need some airflow, but probably not enough to cool a 1200W vacuum motor. Given the small size, i'm hoping I could get away with vaccuming at the end or a job (I may add some modifications to the enclosure to make cleanup easier.)

I know this is very rough and not a particularly inspiring build. This is my first time modifying a machine to suit rather than just taking something off the shelf. Once I have a better idea of the design, I will start to model it properly in fusion and eventually add really photos once I start construction. Any advice would be greatly appreciated.