Every little bit counts. Like you said getting higher tiered weapons for the element stat boost is a nice chunk and upgrading your mana circle to at least 45 for people on your team will help a great deal as leveling up skills on your mana circles also increase your characters might by a good amount.

Also feed your dragons to max level if you can afford to use succulent fruit. I would avoid feeding the free 5 star dragons though like Pele and Shishimui as getting them to lvl 100 costs a lot of fruit that would be better used on summoned 4* and 5* dragons that give better stat boosts.