We are here at the BC and we saw the Friendship boat to DHS start running at 7am for an 8am opening on Tuesday, March 3rd. Both the boat that was at the dock at 7am and the boat that was at the dock around 7:15am would have gotten you to DHS in plenty of time to get into the park before the park opening at 8am. The 7:30am boat would have gotten you there very close to park opening but if lines were long you might not get in the park in time to get a guaranteed boarding group for RotR. If you can get one of the early boats then there is no need to walk or take an Uber/Lyft/Minnie Van or taxi, imo.
They ran the Friendship boats a few hours early for opening day of the Mickey and Minnie Railroad, March 4th, but there wasn't any notification that they were going to do that.
They don't run usually buses to Hollywood Studios unless the boats are down, like for a thunderstorm with lightening.
They Skyliner started running at 7:30am which would have made it a little too close to opening time to get a guaranteed boarding group. That being said, we were able to get a backup boarding group yesterday at 8:35am and they were still passing out backup boarding groups at 9:12am this morning.
They have been giving out guaranteed boarding groups for Rise of the Resistance right at park opening for one minute or less. At 8:01am they have been giving out backup boarding groups. A guaranteed boarding group means that they will give you a fastpass and a one day park ticket to return the next day if the ride breaks down and your guaranteed group doesn't get called. The backup groups will not receive any benefits, like a fp, if they can't ride it.