Changing the scale in symbol manager is done on a one for one symbol basis. So if you did it to a single tree symbol, then that particualr symbol would be rescaled and also placed at the new scale, but not "all trees". Symbol manager also only shows you symbols you've used in your map so far, so it is impossible to use it to use it to change scale of future symbols you haven't used yet.

Also remember that the scale you set in symbol manager will represent the default scale of the symbol, but a symbol will still be affected by the current symbol scale from the symbol parameters dialog.

No. You need to scale them one by one in symbol manager. And note there is no concept of original scale. Once you have scaled something, the actual entities are changed, it's not something that can just be turned off again. You need to scale them with the appropriate reverse operation (for example, if you scaled them to 0.5, you need to scale them by 2 to get them back to the original size.)

Are you sure you used the same symbols? I did a quick test, and SiA obeyed the scale of the symbols according to the symbol manager. Note that SiA uses the default symbol scale for the map though, so while manually placed symbols are also affected by the scale from symbol parameters, SiA is not, it fetches the default value from the drawing presets dialog instead. Of course, there is also a scale option inside SiA, if that is set to anything but 100%, that will also change the scale the symbols are placed at.

You can find an explanation in this FAQ topic:

Yes, that's the most likely explanation.

A alternative explanation is that you simply didn't notice there was more pages. Opening a thread shows you the latest unread message, which would have been Medio's on the bottom of page 2. If you didn't notice the page counter wasn't on the last page, you may simply not have realized there were further messages there.

Try installing the latest update. After doing that, if the buttons are still missing, manually run CC3MenuConfig.exe found in your CC3+ data directory.

You.

Remember, you can search for text in maps using either the atlas online search, or by the search in CC3+ itself using the atlas index.