Tools for library management?

[Jnan_devi]

Gentlemen - I m about to buy dBpoweramp, need some help/inputs/tips. I saw the features  and seems like it is a good tool.

Any inputs on DSP feature usage in the dBpoweramp ? should we even use it or let it go on the default settings?

Specifically looking at these is these any use for for hires usage ?

1) Dynamic Range Compression   level-out large changes in audio level - [Jnan] what does this do? does it increases/decreases the low to high volumes, like in classical music ?
2)  Volume Normalize   adjust volume in many different ways - [Jnan] any idea what is this ?
3) Bit Depth   set sample bit depth (example 24 bit to 16 bit) - [Jnan] If i m ripping CD, the bit depth is as original as in the CD correct why should we modify that ? or is it if a CD is on 24 we want to reduce it ?

There are many features in DSP which I dont want to explore for now. 

Last question : do i need any other tool beyond dBpoweramp for ripping, tagging, format conversion etc ? or this tool is complete ?