1.By boat it's all dependent on how long you'll wait for a boat to come,if you're lucky and get on a boat as you're walking up to the dock you're talking 30-35 minutes as the boat will also make stops at the Swan and Dolphin,Y&B Club and the Boardwalk.If you have to wait for a boat to come then add on the time which could be 15-25 minutes,if you're getting on the boat as DHS is closing and there's a huge line waiting for a boat you're talking 1 hr 15 minutes or more as you may have to wait for a second boat due to the line.The other options are to walk which is a 20-30 minute walk depending on walking speed or a bus to the front entrance of Epcot which would be a normal bus wait,0-20 minute wait for the bus and 15+ minutes to get to the park.
2.The time will also be dependent on waiting for the next ferry to arrive and load,it doesn't take that long for the ferries to get to MK,about 10 minutes so I would put the time to get to MK from the TTC at 20-30 minutes.
3.The express monorail between the TTC and MK is usually pretty fast,even if the line is down the ramp I would say the time it takes will be less than the ferry,10-20 minutes unless the lines are longer than down the ramp,if so bump up the time.The few times I end up parking at MK I'll usually take the monorail to MK and the ferry back at the end of the night when I see ginormous lines for the monorail,I always tell myself even though the line is also huge for the ferry it holds more people at once.