Looking at the Diawa Ballistic spinning reel primarily for inshore fishing bays and flats. Deciding between the 2000 or 2500. Would either size, 2000 or 2500, be a good size for inshore? Thinking the lighter 2000 May be a better option.

Lotsa folks seem to think they need heavy gear for inshore fishing. Although I primarily flyfish, the bride and I do have several inshore spinning rigs that stay in the RV. They are all 6' to 7' light and medium light rods with various 500, 750, and 1000 size reels from US Reel, Okuma, H2O, and Shimano. All hold plenty of 10 lb. test braid and neither of us has ever been spooled yet. A 2000 should more than suffice; just buy a reel that balances with your rod.

I grew up in south Florida and the standard on my spinning and levelwinds was 8 pound test. I caught tarpon, snook, barracuda, bonefish, permit, jacks, specks, mackerel, grouper, snapper, sailfish, dolphin, and more, and occasionally sharks, on those rigs. I got spooled a few times (mostly huge cudas and wahoo) but hey, the fish have to win sometimes too. Don't be afraid to go light. It's a whole lot more fun.

It boils down to preference, I like the 3000 over the 2500, same weight with more drag. I use 20lb braid on a 3000 so I can set the drag a bit higher when using rigged plastics or single hook live bait and move fish off of structure if that is where they are hanging.

Stradic 2500FJ with 30 lb Fins XS (30 lb cuts down wind kots).
Will handle trout or oversize reds.

I agree. I use a 10/100/1000 series (depending on the brand) spinning reel at the coast without an issue. I've landed black drum up in the 35-40 labs class and never thought I didn't have enough drag to properly fight the fish. I too throw lighter, fast action rods, so when I do occasionally hook into a larger fish I'm never concerned about having enough drag, but am more worried about potentially snapping my rod.

Like Jim said balance is important thing to consider. The larger spinning reels are too heavy and clunky and could make matching a rod more difficult. Plus, I throw artificial lures almost exclusively and an overall light rod/reel combo is a plus over the course of a fishing trip. Again, like Jim said, I spool my spinning reels with 10 lbs braid and that's more than enough line for inshore fishing.

Basically, if you're looking for a spinning setup for targeting trout and slot reds I would go with the smaller, lighter reel. Take your rod with you when you purchase the reel and see how the setup balances.