You can use
Photo Contacts Pro to assign certain ringtones for certain contacts
As for volume, well I know for a fact that if you want a more loud of a ringer you can use Photo Contacts and set it to "OUTDOOR". When I do that to mine it gets
CrAzY LOUD.
As for earpiece loud, you can try to following reg edit. Some people say they notice a difference while others say we are crazy and its in our heads.
Change Voice Codec (VOCODER) from EVRC to 13k on xv6700
First dial ##778
Tap on "Edit"
Enter Unlock Code 000000
Tap on arrow to upper left hand of screen to reveal drop down menu where it says "Display"
Select "CDMA Settings"
Click and hold on the "EVRC Enabled" line under the Settings column
Select "Edit"
Switch to "Disabled"
Then press "ok"
Click and hold on the "Home Page" line under the Settings column
Select "Edit"
Switch to "Voice 13k"
Repeat for "Home Orig" and "Roam Orig"