I have heard PRL isn't responsive and you want to go through a distributor that responds. TSP is great from what I have read. Most everything I have gotten is through Axion. Mike responds within minutes about any question I have either through email or FB.
Yes. Seatbelt shoulder strap is attached to middle seat. Buckle is shared with the passenger side rear just like the Aspec. Currently they have a dummy steel anchor that the seatbelt cloth buckle strap attaches to. Just toss that and replace it with the middle buckle. Both share a common bolt.
No issues obtaining insurance. Also if it's your family then your health insurance takes the brunt of an accident.
All the mounting points are available in the car for the fith seat.
Looks like pre-orders are live on axion
https://axionperformanceparts.com/products/prl-high-volume-intake-for-2023-honda-civic-type-r-fl5-integra-type-s-de5-2-0t?variant=47613632053536