As others have noted, there’s a lot of overlap—and additionally for me a bunch of stuff I’m not very interested in or which wouldn’t fit me well, so I’d keep only:

• The SRPD73K1: it’s nicest-looking dive-style watch of the bunch.
• The Flightmaster: I did all my engineering labs using a slide rule even though it was the 1990s and even the professors thought this was ridiculous; the bezel-size circular slide rule might be too small to be genuinely useful, but it’s still very cool.
• Maybe the SNK80x: it’s cute and small (but really: three Seikos?)
• The PD-1701: I actually have (and prefer) the PD-1644, but you can’t beat the Pagani Design photocopier + Seiko mechaquartz movements for value: inexpensive, amazing specs, don’t need winding, the ticking small seconds is unobtrusive.
• Maybe the Bulova Surveyor: I’d prefer (and indeed actually own) a vintage tuning-fork Accutron, but the smooth sweep of the Precisionist quartz movement is cool and reliable too, and with lume and a quartz movement this is a perfect grab-and-go GADA watch.

So, that means saying bye bye to:

• The small Citzen quartz: a sensible size but I’m not a big fan of this PRX-like look.
• The Citizen diver: the only actual dive watch, but it doesn’t float my boat alas.
• The Citizen C7 NH8391-51EE: I actually like the look of this one better than the Surveyor, but it’s in the same category (black dial GADA watch), has much less lume, and will not be useful as a grab-and-go watch.
• The SSK001: just too similar to (but not as nice as) the SRPD73K1
• Both G-Shocks: just too chunky for my wrist, alas—but I’d keep the 2100 if only it was more like 38mm.
• The small white-dial Seiko 5: I like the white dial but are those gold hands? Also, you already have enough Seikos, and you definitely don’t need two with the non-hacking 7S26 movement.

(If I were you, though, I’d keep the SSK001 rather than the SRPD73K1, and at least one of the G-Shocks.)

What would I get instead? Mainly I’d say that you seem to have quite a bunch of $100–$300 watches, and I think you should consider moving towards fewer but nicer pieces.

• Something from Tissot (e.g. PRX, Gentlman) or Hamilton (e.g. Khaki, Murph) would be an obvious choice.
• You seem like Citizen, and I hear they make some great radio-controlled solar quartz watches—the ultimate in set-and-forget. Jody loves his Chronomaster AQ4030-51A, but if $2K is a bit steep there are other options.