Some questions:
For Fight:
Single target: One character - any one character? Do you have to be engaged with that character? Because…
Paces suggests not, allowing you to hit one character, plus one character you’re engaged with (for 2 successes)
Presence: All enemies with whom you’re engaged - so I as the wizard can only engage one enemy, but multiple enemies can swarm me. By swarming the wizard, the enemies create the wizard’s only opportunity to use certain offensive spells…doesn’t seem bright?
The rest I get.
Maybe it should have been a Fight, but not if you wanted it to be a tense standoff like you’re describing. Fight doesn’t do standoffs, it does actual fighting.
Single target is one character with whom you are engaged. It doesn’t say so, but that is the clear implication and the rules fall apart if that’s not true. Paces lets you hit any number of targets you’ve engaged as long as you spend two successes on each beyond the first. Presence works as you say.
Unfortunately, as the Fight rules were written to handle melee combat, they failed to make allowances for spell casters to engage multiple targets with an area of effect spell (after all, melee weapons are limited to one target at a time, so a single engaged target makes sense for them).
I don’t want to take this thread too far afield so I will open a thread in Sparks to seek a solution.
Rules as written, all of your actions are scripted in regards to the opponent that you engaged with at the beginning of the exchange. Once he is down you are either done or in the eye of the storm unless you have another opponent due to being engaged by multiple opponents in the beginning of the exchange. You can only engage a new opponent at the top of the next exchange.
For practical spell casting in Fight! It doesn’t hurt to engage and script with a spell like Fire Fan (pg. 212) or another Presence AoE spell when facing a group. Even if it you are only engaged with and by one of them, it can work without doing friendly fire to your party, and if the gang of mooks are gunning for you, it gets them too.
And as odd as it seems, for all practical purposes a one action spell has the same effective “weapon speed” as a dagger (you don’t have to rest between castings). Although, miss cast spell is a lot more interesting than a miss thrust dagger.