I did something similar with an broken Acer laptop. So I can give you some hints.
So, to my question. What are my options?
I had the same issues with the battery charging and in the end it was to complicated for me. I used an dual voltage power supply I had laying around. So not really portable, but it works for me. If you come to a simple solution, I would be interested.
Keyboard and Touchpad
The touchpad has probably an PS/2 connection. You will need an PS/2-to-USB adapter. The cable is probably an CSI/DSI ribbon cable with around 12 pins. I did not use the ribbon cable but soldered directly to the touchpads board. This was an Synaptics TM540. There are some how-to's for an TM1004 chip in the net. These worked fairly well. Only the left and right mouse buttons were on other pins.
The keyboard has probably only an CSI/DSI ribbon cable with max. 26 pins. You will need an keyboard controller from an old keyboard. From an USB keyboard or from an AT- or PS/2-keyboard if you use an combined PS/2 keyboard and mouse adapter. More on the keyboard connection I wrote here:
http://www.raspberrypi.org/forums/viewt ... 40#p681340
I did not follow this road very far, but you can use the speakers with an amplifier. It did work with an amplifier I had here, but this one was to large. It should work with something like an PAM8403, but I did not test it.
I decided in the end for an USB soundcard.
I put an activ 7 port USB hub in the case. One port is powering the Pi, two ports are for internal use (not used at this time) and 4 ports are going to the outside.
I used an Pi B+ and replaced it in the last days with an Pi2B. Of the four USB connections on the Pi are two free, one is for the combined PS/2 keyboard and mouse adapter and the last goes to the USB hub. For the last I soldered a new cable with only the data lines to prevent backpowering.