I am still a little confused.

But thanks to all who answered. I have been to all the parks many times but have always taken the bus or the monorail.
This year, I have had some knee surgery and I need to cut some of the walking time if possible. I will have to use a
scooter in the parks. Just making it that far has me a little concerned.
You might want to look into
renting a scooter from one of the off-site places. That way, you don't have to worry about how far you will walk and whether or not there will be scooters left to rent once you get there.
You will find more information about renting in the disABILITIES FAQs thread.
Could I take a cab to one of the resorts on the monorail line and then just get on the monorail there? This would be a lot closer wouldn't it? I probably will have breakfast at CR or Poly at least once. I know the bus to MK & Epcot lets you off a long way from the parks entrance so there is a lot of walking there.
The Epcot buses are quite a walk to the park entrance. As cranbiz pointed out, the taxi stop is by bus loop 1-8, so the walk from the buses and taxis at Epcot will be about the same (a fair distance).
To get to MK, it would work to take the monorail from CR or Poly, but there will be a certain amount of walking to get from where the taxi leaves you off at the resort to get to the monorail station at the resort.
ALSO, once you get to MK, there is a VERY steep ramp that goes down from the 'higher-than-second-floor' monorail station to the ground. If you plan to leave the park and get a taxi from one of the MK area resorts, you would need to walk up that steep ramp to get from ground level up to the monorail station. The monorail station at TTC has the same type of very steep walkway, so I would not recommend taking the monorail from TTC either. There is not an elevator at either the TTC or MK monorail station.
If you go to TTC, the boat is a little farther walk, but is pretty much level.
The bus at MK will actually be the least total amount of walking
and it is more level ground than the other ways.
As far as the AK & HS, would a cab let me off closer to the entrance than the bus?
Any other tips will be appreciated
At AK, the buses and the Handicapped lot are in different directions, but I would say the distance is fairly similar.
At HS, the bus stops are the closest to the entrance.
There is a poster named Robo who creates some really great maps; hopefully he will be along with one to show you the compartive distances.