I'm compelled to asnwer a few things in several posts. I do so in hopes of clarifying some areas of confusion.
I know that the map editor opens with a default setting of 96 x 96 for both ground tiles and movement tiles but that does not seem to work out well. The "showoff" game for Coldstone (Pillars of Garendall) has ground tiles of 96 x 96 and movement tiles of 32 x 32 which is an even division making three movment tiles along each side of each ground tile. The map dimensions for outdoor maps are usually 200 x 200 movement tiles, the indoor maps or caves can be 100 x 100, 50 x 50, or even 25 x 25 movement tiles. In none of these maps do the ground tiles fit exactly on the map but always hang over the edge on the east and south sides. Experiments have shown that the maps can have as many as 440 x 440 movement tiles without a problem if the ground tile to movement tile ratio is as above.
Movement tiles of 30 x 30, as Debra uses, also seem to work out fine even though the movement tile edges will not line up with ground tile edges very often.
I have experienced no problem with access being only one tile wide. In fact, if the player is to travel a diagonal path, only the corners of the tiles with access need touch. Even with movement tiles which are only 30 x 30 pixels the playing character has some latitude in movement within each tile. With most sprites, the playing character can walk along the top edge of the tile, the bottom edge, or across the middle. The sprite takes about three steps on each tile as he crosses it. In the pictures showing the random placement of the character crossing the bridge, I'm wondering if this is because the movement tiles are just set too large. Each step of your sprite covers about 10 pixels which means it takes him about nine steps to cross a tile if the movement tiles are set at 96 x 96 pixels.
If you place a character on a tile which has access blocked in all directions, the character will not move, but if the surrounding area is not blocked, he can move a short distance without leaving the tile on which he is standing.
If your movement tiles are 96 x 96 pixels, please try this:
° Change the setting for movement tiles to 32 x 32.
° Change the map dimensions to three times what you now have.
° Completely redo the access portion af your map to conform to the new movement tile size.
This will, I believe, fix a number of the problems you are experiencing.