I added Jolt for thematic purposes. If spells are going to proc this effect, then it makes sense for it to involve the job's "red magic". Jolt still sees use in situations where you get no Verstone/Verfire procs and have Acceleration on cooldown, though I guess the proc chance could be adjusted (increased to minimize the use of Jolt). An alternative would be to tie Acceleration to it (Veraero/Verthunder cast while under the effect of Acceleration grant Enchanted Blade), though I'm not a fan of this since instead of receiving the effect through regular gameplay you're getting one from the burst phase (which can be interrupted if you get a boss that becomes untargetable) and one from an ability on a 35s cooldown.
This is a fair point. I was thinking of just letting it work with Reprise too, though the mana saved is not worth spending the proc. The effect is really meant for Riposte/Zwerchau/Redoublement and Moullinet.2) "Weaponskills" is a broad definition, which includes Reprise. Attempting to stock several charges could also limit our mobility in an effort to avoid spending them on Reprise by accident.
In situations where you need to get away and it's off cooldown, you are definitely going to use Displacement. The rest of the time, you're right that Engagement would be used on cooldown. Given my opinion on the forced positioning thing (read: it's... but then you run into the alternative scenario where nobody ever uses Displacement as an intended punctuation on our melee periods -- which is to say, nobody ever uses Displacement, period, instead just standing in melee and popping Engagement on CD.stupid as hellreally tacky in a poor attempt to look cool), I'm not really bothered by this outcome.
If mobility is a concern, I'd suggest separating Engagement's cooldown from Displacement in exchange for reducing or removing the latter's damage component. At least for the way I play RDM it'd be really convenient, since I'd have 3 oGCD skills to use between Dualcasted GCDs (Fleche, Contre, Engagement) and can leap away from an enemy in times of need.