I strongly recommend you to get unifi installed first so you can conceal the fiber cord.

Anyway from your explaination I can say you are on a landed property and yr cabling is underground from the DP. Anyway that doesn't matter.

I strongly recommend you lay 2 LAN cables to your AV room / TV area. Also plan where your router/BTU is going to be placed.

Make sure you install extra power socket outlets in your living hall / TV area and your workstation area. 

Since you are going to do renovation, I also encourage you to pull a LAN cable to all your rooms for future proofing just incase wireless is not sufficient. Also remember, going wired is the best and most stable way.

Just my 2 cent of input.

BTU does not need to be close to phone port since you will get a cordless DECT phone but it would help if you want to place the phone somewhere else.

For my case, I have FTB and BTU together inside my store room where the telco pit is located. The router is located in another room together with all my other network stuff. I have the DECT base unit in the store room as well near BTU and a DECT extension units each for living room downstairs and master bedroom upstairs. The DECT base placement is not ideal but my original phone line from the DP in the store room to phone port in other rooms are quite bad quality and noisy.