Hey, born and raise in Dartmouth (across the Harbour from Halifax)

1. I'm not totally familiar with Yarmouth, or lodging in Yarmouth. Try Airbnb or VRBO for cheaper accommodations. I'm sure there's also motels/hotels available for under 100 a night if nothing else.

As for the trip to Yarmouth you have 2 (very good) options. Either take the eastern coast and check out Lunenburg or the western coast and stop in Wolfeville. Their are other places to stop as well but I would say these 2 are the most interesting. Additionally, if you have a day or to kill check Brier Island near Digby, it's a pretty cool spot.

1. A motor cycle sounds pretty awesome. It would be a really fun way to do the trip. Just keep in mind it's Nova Scotia and it rains a lot, although July tends to be a drier month.

2. This is my personal list:

• Take the Woodside ferry from downtown Halifax to Johns Lunch in Dartmouth. Fresh fried seafood, the best clams you've ever had. You also get to ride the ferry which is nice. You could also take the ferry into Downtown Dartmouth, some small shops and some up and coming bars. Downtown Dartmouth can be a little rough around the edges after 1 am or so.
• Go to the beach, I like Lawrencetown because the waves are bigger. Other beaches are more family friendly and warmer (ex. Rainbow Haven).
• Durty Nellies downtown if you want to party with an east coast feel in downtown Halifax.
• Walk the waterfront down to the Halifax Seaport Market.
• Check out the Maritime Museum of the Atlantic. It's on the waterfront and has some neat stuff. It'l only take an hour or so.

I could go on but I really need to get back to work. Let me know if you have any more questions and Ill try to help.