A common way of fitting a Coercer for combat is the “beam shield Coercer”.
Dual Light Beams, DC2 and Heat Sinks in the low slots, either two medium shield extenders or an afterburner and medium extender. Rigs: Current Router, Collision Accelerator, Cap Control Circuit - though you may want to play with them depending on preferences.
They’ll normally be Compact Extenders, which aren’t the cheapest thing though.
Everything is skill dependant, but with the shield beam I get the same DPS as your fit, better tracking though slightly less range, and a smidge under 8k EHP tank for the AB fit, and 10k EHP for the dual shield.
Which works best depends on the situation - whether you are the attacker or the defender in an engagement.
Cap stability is over rated - player v player combat is very violent and thus short. If you’ve a minute or two of cap, that’ll be more than enough. Buffer tanks are more common than active tanks - one less thing to worry about, one less thing to go wrong and one less capacitor demand on a ship that already has a thing for its capacitor usage.
Generally the Coercer has no tackle or range control beyond, lets be honest, distinctly Amarrian levels of brick-ish movement. Hence a beam fit - you may need to reach out to touch them with god’s light. This is a common issue with the smaller Amarrian ships. However, the Coercer can put out enough DPS that you can normally melt the target before they escape.
Good luck and happy hunting!