It can be uses as a party buff just fine at the end as several classes have openers that extend past TA going by my raid buff alignments. If you use it early, not only do you not have it up at its strongest for VerHoly/VerFlare and Scorch, but it happens long before any other melee classes uses their big hit moves (like DRG going into LotD within the opener).
But as Kitfox stated, jobs start their burst much earlier than your openers assume they do, and in a normal party of players using openers sourced from The Balance (which the majority of people doing Savage and above would be looking at), Embolden would come out much too late to be of any use to anyone else.

Reprise is used to manage you black and white gauge so that it doesn't go over 50 before Manafication. I did make a mistake with the VerAero before the Swiftcast as it should be VerThunder and I'm not 100% on the Manafication buff times, but the simple solution is to put it after the second Reprise and double weave it with Corps-a-corps. Just not 100% on if doing so will put you below 40 gauge for one of the two bars depending on VerFire and VerStone procs.
Manafication's magic damage buff lasts 10 seconds and delaying even 1 GCD pushes Scorch right out of the window. For what it's worth, Reprise is very rarely useful as a tool to manage your mana, and it is 100% not worth it in the opener. It's potency is too low for anything other than using it for movement to the point where dumping excess mana before a Manafication is achieved by using Enchanted Moulinet in single target when your mana is above 69/69 as Manafication is about to come off cooldown.