1) so if i bought a premium ver so i dont need anymore to use lsclient in the loginscript ? all the data supposed to be taken from my active directory ? (and i f i am deleting computer account from my AD or adding..it will be automatically update in lansweepr database ? )
That is correct except for the delete part.
Computers are never deleted from the lansweeper database. (next version will support this)
2) how can i tell to lansweeper to force active directory computer scanning/sync at this moment ? and not to wait a long days untill the xps computers will perform reboot and only then will be able to enter to lan sweeper database ?
You can't. Active scanning scans the computer as soon as they authenticate to a domain controller (which is several times a day)