I see you're in Maryland too!
I love seeing new people on here from MD.
The submissive peeing - my dad's female dog used to do this, too. Whenever they walked in from being away, she would just get sooo excited. She is now almost 2 yrs old and still does it sometimes, unfortunately. But it has gotten better. We find that when we walk in the house w/ her, to just completely ignore her. It seems mean, but if you don't show excitement, then she is less likely to. Tell strangers/guests to just walk in the door and don't give her any attention until later when it's calmer.
If you're going for the crate training, you should start off giving them a small space. Dogs naturally usually will not potty where they sleep, but if they have access to pee in one corner, and sleep in another... it defeats the purpose of crate training, lol. I would just gradually give her more space over time. Jackson started out in a small crate, then I bought an exercise pen from Kmart that he stayed in while I was gone, and now he stays downstairs (we still block the upstairs) while we're gone and he's now 11 months old. Trust me -- the day will come! Potty training these little stubborn dogs can be TOUGH, just have patience and stick to a schedule and you will be successful. But remember Yorkies are known to take up to a year to fully potty train.
A ton of people leave their dogs for 8 hours a day. People DO have to work and there's nothing wrong with that. However; I think a 12 week old puppy should really be let out once during that time. Their bladder is just so tiny at that age and really shouldn't be expected to hold it that long. I would find a doggie daycare in your area, or a pet sitter to come by 1x during the day, or come home from lunch, etc. It doesn't always have to be like this but I think a 12 week old pup needs to be let out once during that day. The "rule of thumb" is that they can hold it for however many months they are, plus one hour. So a 3 month old dog can hold it for 4 hours.
Bottom line: it's really about works for you!
I would just learn her schedule, what she's good at and comfortable with. She will grow out of the puppy stage faster than you think!
I hope you continue posting here and can't wait to see pictures of your little girl.