in wavelet transform only approximate coeffitients are further decoposed into uniform frequency subbands while in that of wavelet packet transform both approximate and detailed coeffitients are deomposed further into sub bands.

dont-know

Wavelet tree is recursively built applying decomposition and approximation filter only to the (father wavelet) approximation filter output at each step (or level).

Wavelt packets, instead, are constructed by applying both filters to approximation and decomposition filter output resulting in a 2^(n+1)+1 nodes with respect to 2(n+1)+1 nodes of standard discrete wavelet tree

With Daubechies you can use practical subband coding scheme. You don't have to no the actual wavelet and scaling functions, but rather you need to know low-pass and high-pass filters related to a certain Daubechies wavelet family.

The diminutive of wave is wavelet.