Thank you for your great site.
May one take a Sefer Torah out of the Aron Kodesh to practice doing hagbah on it?
Halachically it is not permitted unless you will be reading a number of pesukim from the sefer torah first. Even if you will be reading from it, according to a number of poskim it is not a correct thing to do, because a sefer torah is not something to be used for practicing. (There are other things that can be used to practice). See Chashukei Chemed -Megillah pg. 326. Also see Chashukei Chemed Bechoros 60a that in a case of a strong need it would be permitted, such as in the instance that he talks about over there.
חשוקי חמד מגילה עמ’ שכו’
ועי”ש מס’ בכורות דף ס’ ע”א