First, I agree with you with respect to ROMs & Apple. However, technically, this is not against posted forum rules. Since ROMs are just software, and long abandoned software at that, they certainly fall under the abandonware moniker, regardless of how the vintage community has traditionally treated them. So the real issue is not whether this violates the written rules of this forum, but whether our members should be so blatant about flaunting the law. It's one thing to post a link to something (which I mostly frown upon because it only easily highlights to Apple for shutdown a vital resource for vintage enthusiasts), but quite another to openly conspire via a public forum to violate copyright law. The usual response to these concerns is the open disdain shown in this thread. I'm not sure one could expect anything less after a generation of kids have been raised using Napster and Limewire and where 60% of all music today is still downloaded illegally by teenagers rather than legally purchased by legitmate means.
Second, you are wrong about how both Basilisk II and Sheepshaver work. In particular the Classic ROM is required for Basilisk II to support certain software (though you are correct about the IIci/Quadra era ROMs). Sheepshaver also requires specific ROM versions and cannot just use any ROM (but they all run the same way). So all the popular emulators, require specific ROMs and emulating the Classic, requires that ROM in particular (which Sheepshaver doesn't support). As for the PowerBook 100 ROM, I am not sure why anyone would need this, except for Mini vMac which still does not fully support it – unless one wants to contribute to the development of the PB 100 Mini vMac emulator. Nothing else will support it. Also, running a PB 100 or Portable emulator offers nothing over an SE emulation other than system specific power management features, which wouldn't function on an emulated machine anyway because they are hardware supported. However, they do support 640x400 screen size which doesn't really offer much more in compatibility than extra screen real estate (i.e. games that require 640x480 won't work on it).