I don't have a disabled tag, but was told to tell the CM at the front of the line directing cars that I had a
scooter in the car and he would direct me to somewhere appropriate to park. The furthest back I parked was row 5 in one of the reserved rows, and the nearest was literally 30 feet from the path to the entrance to AK.
I was also allowed to park in the disabled areas at the resorts when we went for our ADRs.
they do save some spots for guests with
ECVs who do not have handicapped parking permits.
They are sometimes at the ends of rows in the closer regular parking or there are some spots in some handicapped parking lots that are OK.
Handicapped parking spots with signs or blue paint are the official handicapped parking spots and parking in those without a permit could get you a ticket.
The spots in that area with white paint are ones where guests can park without a handicapped parking permit.
I need to add don't ever park in handicap parking without the proper hang tag the Orange County police patrol and don't care if you were told to park there by a Disney cast member

If you don't have a valid handicapped parking permit, you can get a ticket. As bidnow5 mentioned, the lots are patrolled by the Orange County police, and people do get ticketed according to Cheshire Figment (a frequent DIS poster and CM until June 2014, when he retired). My family has seen them patrolling and have seen tickets being written out at Downtown Disney.
One year when we forgot to bring our handicapped parking hang tag, we were told that if we parked in the marked handicapped spots, we were parking at our own risk and could be ticketed. In checking with the police, we were told if we were ticketed, we
maybe could get the ticket dropped or the fine reduced by appealing the ticket with a copy of our DD's handicapped permit.
We took the bus a lot that trip. Because she is not able to walk or stand, we had to park in the handicapped spot, do drop off or be in the perfect non-handicapped spot (end of row with a clear space next to the vehicle large enough to park the wheelchair and lift her out). We put a note in the windshield explaining that we did have a permit, but had forgotten it; with our WDW parking paper, they would have been able to find us to verify need.
We didn't get a ticket that trip, but were pretty nervous every time we parked in one.
for MK:
You can take the internal Fort Wilderness bus to the Settlement Depot, go to the boat dock and take the boat to MK. (you can't park a car at the Settlement)
That boat is WC/
ECV accessible and drops you off very near front gate.
"There are 4 routes available in the Magic Kingdom area, each designated by a colored flag. Each route operates 30 min prior to park opening including Extra Magic hours until 1.5 hours after park close. The boats may cease operation due to inclement weather."
"Green Flag Launch: The green route carries guests from the Magic Kingdom to Disney's Fort Wilderness Resort & Campground. This is a heavily traveled route due to the Hoop De Doo Revue and Mickey's Backyard BBQ being at this resort, along with the fact that guests staying at the resort can only get to the Magic Kingdom by boat. This route typically runs two cruisers which are both capable of accommodating ECVs and wheelchairs without a required transfer. Travel time from Magic Kingdom to Ft. Wilderness is approximately 13 minutes once underway. Wait time between boats is typically 10-20 minutes."
http://www.wdwinfo.com/transportation/water.htm
We have been to Trail's End restaurant several times, using different methods to get there.
If you drive, parking is by the main front area, near the check in area for the resort. From there, you take buses to get to the area where a Hoop De Doo, Trail's End and the BBQ are located.
From MK, you can use the buses - 2 buses, one that goes between park and resort, then an internal bus.
You can also use the boats. If they are not using two cruisers, then every other boat will be a small boat which is not wheelchair or ECV accessible. Because only the large boats can carry ECVs and wheelchairs, and can only carry 2 at a time,you may have to wait for the next boat.
On one of our trips, they were only running one cruiser and it broke down. The transportation CMs in the dock area advised those of us who needed accessible transportation that our only option was the buses since the othe boat was not accessible.