1) aliases have NO leading prefix, if your putting one in your wasting harddrive space
aliases
/blah { echo -a blah? }
///blah { echo -a blah? }
blah { echo -a blah? }

are all the same!

So set your prefix to \ then / and \ well work

3) //set -l %t 0 | echo Total files were $findfile(c:\log folder,*.*,0,inc %t $file($1-).size ) total size was %t bytes

5) yes (see RusselB's reply)