UPDATES 2015 to later 2015

There seems to be another update to sketchup 2015 to a newer 2015. Will I lose my layout scrapbooks and templates if I update? What is new in this update?

Here is a link to the release notes –

The release 3 is for both, Pro and Make. If we have Make only, can we just still use this upgraded?
If we download release 3, do we still need to upgrade with release 1 and 2? (I don’t have 1 and 2)
Thank you.

the recent maintenance release does update all previous releases of the according version.

Where do we click to get Release 3 for SU 2015 Make?

latest version always here, may need some time to be updated after the release of a new Maintenance Release.