I don't know that expanded deck crew is so desirable on the Tempest. Somewhat faster drone recovery for an ability that doesn't do all that much damage isn't such an extreme benefit.
Main issue I see is that it's not exceedingly fast or well-shielded, so its ability to survive the occasional mistake that'll definitely get made by the AI in an extended fight is very limited.
Honestly it really is very fast, it just doersn't have a system that briefly makes it
extremely fast.
Also, I agree, I don't think EDC has enough of an impact on the Tempest to make it worth that 8 DP when you have many other options to spend that DP with for a ship with a similar role. However, EDC is great with bombers and, well, terminator drones in AI hands are basically bad bombers, so it does help. Tempest alternatives; Wolf, LP Brawler/Lasher, Scarab, Medusa, TT Brawler, Glimmer, Lumen, Omen, all of these fulfill "Fast, capable of fighting enemy frigates with the right builds." Some of those ships lack PD options compared to the Tempest, but the Tempest also almost never has its drones around for PD unless you give the tempest long range beams and a cautious personality.
By the way, wouldn't it be funny if AI Tempests actually used 1 of their terminator drones on repeat if you gave it nothing but long range beams? Maybe trying to keep their RR at 100% before launching another. Then they're sort of like... weird 'infinite' missile frigates. Not saying they should do that, it's just a funny idea. Right now the tempest just goes to 30% RR so it's like they have infinite missiles, but really don't.