Scrolls need to be made like Pots, so they can be used without actually equipping them. This would address several issues.....
Reason #1: Buff/Modify weapon can't be self targeted because it needs to be in main hand and MANY weapons can't be held off-hand (I'm looking at YOU 'Deadly')
Reason #2: Equipping a scroll in an emergency to help/save a party member (or yourself) can be extremely difficult if not impossible during a fight. beasties aren't terribly understanding when you put away your weapon to read stuff
Reason #3: Lag can prevent the re-equip of your weapon, and fighting off Reaper Mobs and critters with a sheet of binder paper really bites. I've have several instances where I've frantically tried to re-equip my weapon, with the scroll in question steadfastly refusing to leave my hand for nearly 20 seconds...