The second hit will only happen if you hit the first. The slow can’t assure that because by the time you ‘cast’ Inquisition the enemy already stteped out of searing lash.
Inquisition’s slow happens only during Inquisition’s channel. If you stop it inmediatly you lose the slow, so what’s the point? You claim it’s usefulness is the utility the slow provides yet you say I should cast it and break it inmediatly.
Number tweaks will not make her fun again. This is a much bigger problem.