If you have awesome tanks running with you [like I do], Quelling Strikes isn't exactly needed. It does come in-handy during burst phases though [so you can switch to them right away without worrying about pulling aggro] and during SR's [that Fire II/Flare AOE rotation is an Enmity generator].I've got an archer at about L16; it it worth continuing that high or is there a better cross-class additino for the BLM?
Leveling doesn't take that long, especially if you do the random dungeon/guildhest each day. I'd probably recommend leveling your Archer to 34, just to have it on-hand, but it's up to you whether you think it's worth it or not. Personally, I'd say go for it.
[Plus it will save you from the horror of the sugarloaf hat.]