Is your arrangement created with musical or linear time resolution?
I would apply fermata and accelerando using tempo changes, which requires musical time resolution. If I needed to record a performance that has a lot of tempo changes, I would record without the metronome. Afterwards I would start from the beginning of the arrangement and use the ‘Adjust tempo to align grid at cursor’ right-click menu on the tempo lane to incrementally align the bar/beat lines to the freeform recording. Once you have the grid in place, it will be easier to add e.g. fermata by adjusting the tempo around the fermata note.