Wall tool:

The wall tool is a line drawing tool and doesn't join into a closed polygon. A wall is a line with a width. Conversely, the room drawing tool automatically draws a closed polygon wall (which is rendered hollow by the line width) because it doesn't know where you want the door to be, or even if you want a door.

The bridge symbols meet at the highest resolution. There are 4 images of each symbol in a graded set of resolutions to speed up the zooming process, and where they are fuzzy-edged pixel images sitting on a precision vector reference grid they can appear to have gaps between them at lower resolutions. If you have issues with this it may be necessary to draw another line of them off the map somewhere initially using the snap grid so they are perfectly horizontal or vertical, and jink them closer together by hand. Then the string of bridge bits can either be grouped and moved, or just moved to position on the map.

1) Textures aren't aligned unless they are made to align, and you can only do that with a filled polygon, not a wall. Happily, your floor is a filled polygon. Hide all sheets but the floors and right click the Polygon button on the right toolbar. Click the floor on one of its long sides. The fill will align to that side, but it will also shade like a pitched roof. To get rid of this you need to type EDITSHADING on your keyboard and hit the Enter key. This is a command you have just given CC3. Check the command line at the bottom of the window and see that you are being asked for the entity to be edited. Pick the floor and then in the dialog that appears check the little box called "Shade Only Copy" and OK.

You should end up with something like this. Here I have shown the 2 steps from left to right.

2) Before you place the symbols, but while you have them on the crosshairs ready to paste, right click your mouse and then click the Set normal button and the More button and see if that works better for scale. The stairs align perfectly with the snap grid for me.

3) The interior wall is a symbol, not a fill. I rarely use them at all because they don't match the fills that well. I usually use thinner regular walls drawn with the wall drawing tools, or I draw the entire building in these interior walls.

I think I got everything there?

Just make sure he's not intending to sell them on or add them to a commercial product of his own. Free stays free.

Unless, of course, you really don't mind him making money from a free gift you gave him.

Oh, he's looking for a higher resolution copy? FB uploads are really low res.

I'm not able to help you with contracts, conditions and prices. It's a minefield I've managed to stay out of so far, so I don't have the experience to help you.

That makes no sense at all.

Numbers of copies applies to printed maps, not digital maps. Is that what he means? A printed map, I mean?

The Fisk map is one I've seen many times before, and is always a marvel to me.