for keypad lock copy the file 'Aknnotpi.r01' from Z\resource, and put it in E\memory card,
edit/change the text with x-plore's hex editor, then copy it to C\resource and reboot the handset,

you will see the letters spelling the words 'keypad unlocked' on the right in hex editor, simply change them by changing the numbers in the middle of hex editor, to the letters you want to use, i changed them to 'welcome tutster'

this file also has the text for '1 new message' and '1 missed call'
and '* missed calls' and '* new messages'

before you start this make sure you change the text correctly as you cant remove or edit 'Aknnotpi.r01' after you put it in C\resource, if you do make a mistake you will have to use 'Jbak taskman' app to kill the process then you can remove the file, (im not sure which process to kill) its the same problem with changing the menu name post by 'NIGRA'
i think the files are currently being used so you cant delete them from C\ untill you kill the process

all the other files i mention CAN be removed/edited if you make a mistake as there not being used untill you open the app

for music player menu name, copy and modify 'mpx.r01' & 'mpxmainview.r01 from Z\resource\apps to C\resource\apps