I must say, wow... that was a bit hard to read.
You don't need any practice locks(which I think are made by engineers anyway) to skill up.
There are some instant respawn practice chests in quite a few places. The only place I know off the top of my head is in the lumber mill in Redridge Mountains.
However, since I'm in a good mood:
The Lockpicking guide from the Rogue Class Forums