I'm looking for some help with making my set up tidier

I'm also hoping to make it a bit more kid proof before our 3 month old daughter starts to get mobile and pulls at the wiring looped all around the room!
I have a fairly ordinary Edwardian/Victorian terrace house. like this....
Don't know why my image isn't working?
The 32" TV is sitting on an Oppli Ikea stand with the front 3 speakers TV, cable, amp, Tivo, DVD PS2 and kitchen sink
RR is the right rear and LR is left rear. They're small speakers mounted up on the wall .
The front room and dining room are connected by double doors there is a door into the hall (currently unused). There are two sofas arranged in a L. hence the speaker positioning.
The cable TV and aerial come in under the RR speaker.
The cable TV is running up the bay window and around the fireplace on the picture rail then down the wall behind the chimney along with a phone cable for Tivo.
The TV aerial and speaker cable for RR are running around the bay along the wall on the left, past the doorway and meets the speaker wire for LR. They all go behind the connecting door, over the top of the frame and down behind the TV.
P? indicates a possible projector which I would want to wall mount so I'd want to run a duct to that corner too I think.
I want to run the wiring for LR, RR, cable, telephone and aerial under the floor to behind the TV.
I don't want to damage the floor lifting and refitting as it's on show and has been done really nicely.
I had a very tentative go at prising up one board in a corner with a crowbar but it was very hard work and only the first set of nails came free the second set stayed put - I'm worried about splitting the boards and not being able to do anything but refinish the whole floor

.
Underneath the room and the hall is a basement with plasterboard ceiling which runs full lenght up to half way across the bay (i.e. not accessible under the TV or RR

)
Again I'd prefer not to trash the ceiling in here to route the cables but that might be a better option than ripping up a lot of floor boards upstairs.
So why am I posting

?
The floor boards run left to right as you look at this picture so I assume that the joists will run front to back?
I'm hoping to run one central conduit under the floor in front of the hearth and spurs across to LR and RR.
I'm hoping to do this in one weekend so I need to be prepared!
Does anyone have any great advice they'd like to share - I'm reasonably handy at DIY but I've never been fond of ripping and cutting things that are old and well done
First big question is how do I carefully lift the long original boards without damaging them?
Am I likely to find any real horrors under the floor that will put a stop to my plan entirely?
Thanks for taking the time to read my massive post!