Most of the older rescue Yorkies are potty trained already and if not the rescue group will tell you. I think those Yorkies are very well monitored and the info about them is detailed and correct. There are no "marketing" phrases since the rescue people want you to know what you get yourself into rather than getting a dog back. All Yorkies need is love, love, love, attention, love, tummy rubs, love and ... did I mention LOVE?
Since you are going to have tons of time to spend with your furbaby you will have one happy little camper. As of the training, you are right! Yorkies love to being kept busy and I think letting him/her do stuff for you will make it even better.
Yorkie are not nesessarily hyper. Mitzi is more of the layed back type and sleeps a lot. The best of luck for you!
