Scrolls do not scale with battle elixirs. Just wasted a lot of mats to know it hard way. Also I checked http://www.wowhead.com/item=20744 and can confirm that it do not add stats on battlegrounds. But to your list we can add war drums and http://www.wowhead.com/item=126935 this feast can be not only stats boost, but also moral boost to the team, as it dress every team member in funny cloth and may be randoms can perform better. The feast last only 2 min, so plant it on graveyard only if you have enough mats to craft lots of these feasts.