striking is no go for the bombs, they are already at the correct dices, the property runes is what would change the math.
so, at level 12, the vast majority of weapons will be at 5 dices, 3 from striking and 2 from elemental runes. bombs are at 3 dices, so they are behind.
that's why bomber starts to get left behind around level 10+ which is when martials start putting the elemental runes on their weapons while alchemist doesn't have such "math fixers".
at that point, bombers that want to stay relevant switch to status inflicting rather than damage because they simply can't keep up.
now, i'm pretty sure that the rai was never about the bombs, and going by a reading of the raw that runes can only be placed on permanent items, i'd say that similarily you can't "tranfer" the runes to the bombs either. Which is a shame, but at least we did get at least 1 super poerful status inflicting bomb in the book.
i'd have to wait and see the actual effect all those small buffs that have been trickling down towards alchemist in this book, when put all together, accomplish for the class.
i am hopeful that it will be a little more competitive at least.