Having wired up many a company with Cat5, I did my house the same way.
Not claiming this is the best way, but the reasons I did it ths way are stated.
Firstly,its not a good idea to run phone and data down the same cable. I ran two cables at least to every room and put double RJ45 faceplates where need, or simply left the second wire disconnected inside the backing box if I didn't need it then and there. When laying cables, always lay LOTS. Cable is cheap and its no harder to run 4 than one.
Cables terminate on RJ45 patch panels.
I went with a PABX because the house is large enough to need a lot of phones - 8 currently - and that's beyond line limits for most phone types. It would also be somewhat nasty with broadband - I wanted a single stable predictable load on the phone ine - the PABX does that. It also took 3 doorphones to avoid having doorbells..useful again because from the back of the house you can't hear people knocking. For historical reasons I also had two incoming lines. The only irritation is that you have to 'dial 9 for an outside line'. The benefit is that you ca transfer calls around the house.
I didn't go DECT because my experience of this is that in a house full of metal (and covered in metal lath/render) it doesn't work that well. It was also expensive. I used a cheap panasonicx hybrid PABX - most of the phones are cheap ordinary phones.With a PABX you distribute phone signals on 2 wires only unless you are using a digital phone. That means you need PABX master faceplates for the phones, or PABX master dongles if using RJ45 faceplates.
On up to 100Mbps stuff the ethernet uses different pairs to the phone, so no problems with misconnections.
The phone extensions are wired to a different patch panel and patched across to the house wiring to enable certain rooms.
I currently have a large 100Mbps switch into which the ADSL router goes. That is patched to the ethernet sockets round the house..
The ADSL router plugs straight into the BT master via a microfilter. Filter faceplate would be better..one day.
Since all the wring had to go in, I also ran loads of co-ax satellete cable around the place: Currently I have a distribution amplifier (Labgear) that takes TV and FM signals and boosts them for 10 room sockets.
Also installed loads of alarm cables..but we like the house so much we don't go out anymore..so its not been fitted
Currently got two Macs, a PC and a Linux web server plus netoworked printer running..web server is publicly accessible on static IP address via port 80 pass-through. Plus one networked printer.
Compared with people who use wireless phones and networks, its infinitely more reliable, though people think I am old fashioned