Tiling

Please refer to my bathroom album first.

//www.diynot.com/network/daffyduck1962

I want to build a frame off the wall to cover the pipes to the left of the bath. I plan to make 2 separate section, one either side of the pedestal. Each will be finished in wall tiles.
I want to have the finished article so the tile surface is level with the edge of the bath. Calculating the height for the frame would be easy if I knew how deep the tile adhesive bed needs to be. Can you advise please?
I also need to fill in the void behind the taps, and thought I would use a 2 x 4 baton frame, cover with plywood, then tile. the height of the box will one full tile's height for looks, finished with a small shelf which will overhang and allow shampoo etc. to be to hand. Do you recommend tile strip or silicone as a water tight seal around the bath's edge?
My last bath had silicone but was always turning mouldy. However I have heard that edging strip can become hard and warp over time allowing water to seep in behind and onto the floor.

Baths the wrong way round shower should be tap end as thats where the bottom is level for standing other end slopes so you can't get close to shower and need a much larger screen.
Tiles should never finish flush with bath should always step down to bath for a good seal that won't leak.
I would have dropped the sink waste straight down into the bath waste to leave no high level pipes to hide and just a low box skirting to hide lower pipes
White pipe? toilet/boiler overflow? drop that down before it comes thru wall and run into waste pipe.
Looks like you need to start again.
Silicon only goes mouldy due to poor cleaning and lack of ventilation. Had my bath sealed 18years ago, still clean.

Bath is not going to be able to be moved due to the nature of the waste pipe, same applies for basin and yes it is a condensate pipe for the boiler.
Waste goes throught wall into toilet where it meets soil/vent pipe which is cast iron, and boiler is at the other end of loo.
Not enough drop off to switch bath around and water and power for shower at head end to begin with.

Bonding plaster is an awful idea in a bathroom, it's a pity the render got skimmed as that would have been exellent to tile too. Aqua panel or hardie board is much better than ply too. Silicone things every time, Im surprised you haven't got enough fall on the waste to turn the bath the right way round looking at the height it is from the floor by the basin.