I'm not real good with distances, but I would guess about seven minutes to MGM, 10 to Magic Kingdom, 12 to Epcot and five or less to Animal Kingdom ... depending on lights and traffic. There really isn't a lot of difference in distance between WP and Vistana, but 192 tends to crowd up a bit more than the Vistana routes. Basically you turn left out of the resort, take a brief drive to 192, go through one or two lights on 192 and you're right on the road to Disney. For AK, go left a light and turn on Sherbeth. We also came around that way any time we thought traffic on 192 would be heavy.
The breakfast is for all and is weekdays only I think. It's just danish, juice, milk and yogurt, but my 6yo loved the Trix yogurt every day. Probably coffee too, though I don't drink it so I can't recall. We'd usually just drive by on the way to the parks and grab a couple of things. They said not to take food out of the area, but it was too cold when we were there in December to sit by the pool and eat.
The mini golf is fine for kids. I was thinking in terms of more planned activities at Vistana. That being said, we seldom take advantage of them, though it's nice to know they're there. Also, the area we were in at WP didn't have a pool close by, but they were supposed to build one soon right across the lot from our door. It might be done by now.
We only stayed in the 2br side and it was plenty big for six of us. The 3br will be great for you. Good trade.
Sheila