Partial success Matthew,
First of all as soon as I click on the poly/path button in Google the description panel pops up and that obscures the view.
Move it to the side of the screen.
I do not understand the line tag the poly.
This is done within FSX_KML. Not in GoogleEarth. "Tagging" is the term used to describe telling FS what type of vector data you are putting down.
You tell this to FS within the FSX_KML program. Once you have loaded your .kml file into FSX_KML, you will see on the left side of the screen, a listing of the objects in your kml file. Next to them, is a drop-down list of various tags. Select the one you need and go.
For airport backgrounds, that is usually Airport_Backgrounds_MaskClassMap_Exclude_AutoGen
When I add a name and altitude to the box the vertices in Google disappear.
Don't bother messing with altitude within GoogleEarth. Set altitude in FSX_KML always.
You should be able to name the poly what you want. But don't hit ENTER after typing the name, that will close the window and GE assumes you're done. That's standard Windows convention stuff--true of any windows app.
I cannot then get them back. When I am in Google there is no response to my mouse buttons.
That doesn't sound right, maybe GoogleEarth is not set up right? Really, all you do is
1) load GoogleEarth, go to your area of interest
2) select Polygon button. Draw your area.
3) Save as... kml
4) start FSX_KML. Load your kml file.
5) apply a tag to your poly (I explained how above)
6) click Build, you're done
It really is easy