Q. Are Yorkie Poos alright to be left alone some of the day and are they easily house trained
A. They are not very easily house trained, no. Yorkie's have small bladders, and tend to drink more than other small breed dogs. Yorkie's need to be on a very strict pottying schedule. When they're puppies, they should be brought outside every 30 minutes when they're out of their crates, and when they are in their crates the "rule of thumb" is one hour per month of age, plus one (until they ABSOLUTELY HAVE TO potty). Crate training is extremely important when it comes to raising a puppy, especially one who has notorious issues with potty training.
I could go over a crate training exercise for you so you can start crate training right away. Crate training is a very SLOW, careful, and positive process. It needs to be handled very delicately to ensure the puppy has a positive experience.
Of course dogs are alright to be left alone some of the day. About as long as the "rule of thumb" allows, and absolutely no longer than 8 hours (as I find that just cruel). Crating ensures dogs safety.