We stayed at the Homewood last month. It's a great hotel. The room was nice, the breakfast was very good and the staff was polite and helpful. We did have an issue when our smoke alarm bad a low battery and started beeping intermittently at 4:00 a.m. When we reported it, it was fixed immediately and the front desk agent comped the parking fees for our entire stay.
In terms of the Toy Story shuttle, it is a good option if the lines aren't too long. On the first morning, we drove in from LA and were getting on the bus around 9:00 a.m. The line was very long and we waited at least 20 minutes to get on a bus. The lines were also fairly long for a return bus each night. We ended up using Uber twice in the mornings. It saved the walk to the parking lot and got us to the parks faster.
Regarding hotel guests using the shuttles, I have heard that it's perfectly fine. Disney is happy to take anyone to the parks whether they paid for parking or not. It's good for their bottom line!