Home Cable Run & Network Devices Query

Ethernet run can be up to 100m without loss/degradation, providing good cable quality .

Central network distribution point, whether is kitchen or utill, as long it will provide enough room/access for all network needs for foreseeable future.
It makes no difference where your ONT is located - Ethernet link(or two) to central location will cover that.

Power availability (extension leads are another point of failure)

WiFi AP distribution depending on property size - Ethernet run for each AP from PoE+ (or ++) capable switch
VLAN (optional, but good to have) - separate IoT, CCTV and other networks

Consider CCTV , providing WiFi is strong might not need Ethernet.

10GB link is only useful if both (better ALL) End devices support it, but good to have for future upgrades. Link between two devices determined by weakest device. In some instances, if one device only support 1Gb negotiation of link speed might cause unpredicted outages/issues and might require manual intervention/configuration.

My personal preference - All stationary device on individual Ethernet(PC, TV, printer,) , but local small switch might get that covered

Most above "get it done" if you can, thereafter compromise depend of resources/circumstance.

As long they are 1Gbps , cheap and cheerful
TP-link 5 port gives you 4 available ports, 8 port allow 7 connections
Same brand with PoE should you consider dedicated AP's for WiFi

Note: standard consumer router from ISP usually support up to 32 (64 at best) WiFi devices simultaneously.