xperia play has died

[VIRGIN KLM]

I think you don't need to be rooted to push a wake up through ADB, it's just that it needs to be enabled so you must be sure you had it enabled before your button died.

Costum Kernels and rooting are 2 totaly unrelated things, it's up to the ROM.

My suggestion because a friend had that phone and asked me to do whatever I can to improve it is, Unlock the bootloader with Flashtool, and then install a new ICS or JB rom to it that doesn't break anything XPERIA Play related (there are alot of ROMs that do that) or root your stock ROM. I'd call mandatory all those stuff for Xperia Play.