I think the term 'misguided act of compassion' is interesting. I would not view it as a rescue mission but an arrest. Arresting criminals is not an act of compassion, it's their lawful duty.
If Starfleet was a police department, yes. But it's not. It's a paramilitary organization with a different mandate and substantially different rules of engagement.
Check out this for some amazing refit deck plans:
http://www.trekbbs.com/showthread.php?t=92307
I used to have this thread bookmarked.
Significantly, though, even these are based mostly on the David Schmidt plans. Which I ALSO have saved on my HD because they're awesome.
But in terms of transporters I think the ideas from the TMP plans make a lot of sense. Never mind evacuating the ship, if for any reason the engineering section had to go on a mission without the saucer it could be hamstrung without any transporter capability. It has its own auxiliary bridge, why not transporters?
Cool as they are, those plans were written in the 1990s, at which time TNG had been on the air for years and we knew a lot more about starship concepts than we did when Probert originally designed it. The saucer was intended to separate from the main hull only in the event of a catastrophic emergency -- basically, like the one we saw in Generations -- and could not perform any sort of mission on its own (other than, say, "The saucer just exploded! Abandon ship!")
There's again the issue that the transporter system is a pretty maintenance and energy-intensive device in the TOS years; "The transporter isn't working!" is a valid plot device because it's "The transporter." Singular, not plural. By the TNG years, we get the concept that a ship with twelve transporter rooms could somehow not be able to beam people anywhere just because a console exploded on the bridge.
There are huge conceptual problems with transporters when you aren't transporting from pad to pad.
Furthermore, I don't think it should even be possible to do that until the 24th century. If we think about this, between ST-Enterprise and TNG the differences in technology are almost down to cosmetic touches since everything seems to work basically the same way. In the 23rd, there shouldn't be any possibility -- AT ALL -- of using your own transporter to beam someone off your ship who isn't on the pad. In NuTrek, just beaming down from the transporter room is a complicated and potentially dangerous process, which I find ENORMOUSLY refreshing.