Not a bad idea. I'll just give you some random thoughts on each of your categories:
1) HW30s is wonderful; I have one. Thinking of putting in the Vortek kit, which will add a couple FPE, while still keeping it smooth. It's pretty much in a class of one, until the Diana 24 re-release comes out. But I'm skeptical that Diana quality is up there with Weihrauch's, these days. They're putting those cheezy plastic fiber optic sights on everything... Do also consider the R7. It has the better-looking stock, with checkering, a shorter barrel and a muzzle brake vs. sights on the HW30s. The front sight is hooded, but the rear sight is just an open one. If you're going to shoot it with sights, you'd want an aperture sight at the rear of the receiver, I think. If you're pretty sure you're going to shoot it scoped, definitely get the R7, as it won't have the ugly dovetail grooves that are left when you take off the front sight.
2) TX200, you've read all about mine here already. But you know what? If I had it to do over again, I might open up the ol' wallet a little further and get a ProSport. As a target gun, the TX200 is awesome. But with that solid steel underlever, it is DAMN heavy, and out at the front; very hard to shoot offhand. Any kind of rested position, it's fine, whether it's the classical field target position resting on the knees, braced against a tree, prone, bench... all fine. But the minute you want to take an offhand shot, stuff gets real. For reference, I'm 5'8" tall, 170 lbs., medium build. Not a weightlifter, but not fat or scrawny guy. Just average. I'm already committed, so I'll probably work on shooting offhand more, to develop those muscles. I'd say it is twice as hard to shoot offhand as my Marauder, and about 4X harder than the HW30s. My Stoeger X20 is also much easier to shoot offhand, and it has the same power level as a stock TX200. The ProSport, Air Arms says, is more refined. The anti-beartrap mechanism is automatic. The cocking lever looks to be some lighter material. I presume it is less barrel-heavy as a result. The caliber is a no-brainer: .177. If you want to shoot full power, it shoots 8.4 gr. pellets at around 920 fps, which is perfect: fast and flat, but without flirting with the sound barrier. Or shoot the heavies 100 fps slower or so. Vortek offers kits to take out the buzz and twang, but not lose power. Accurate, yes, but make no mistake, the TX is quite the twanger, out of the box. It'll give you the heebie-jeebies after shooting smooth PCPs or an HW30s. But heck, if you're only gonna have three rifles, you may as well do them up right, right? Go up to .22, and you're down below 700 range, which I don't like; too loopy. Even my de-tuned TX in .177 is shooting mid weight pellets at about 800 fps. Get a .177 Pro Sport and try it out. Detuning it to 12 FPE will make it easier to cock too, which takes away the disadvantge of the shorter lever. I wouldn't overlook the Walther LGU, either. It seems to have done some things better than Air Arms, such as quietness and a smooth shot cycle. Accuracy is at least as good, by all reports. A plastic trigger seems to be the only complaint, and it's less expensive too.
3) I think you have nice .22 caliber PCP hunters already. Don't you have a FX Wildcat in .22? I can't imagine anything more shootable than that. The tougher thing is deciding which ones are going to go!
