Here is a simple wav splitting utility, waveknife:
WaveKnife
There is something called samplerobot 3 which is supposed to automate certain multisample creation tasks in a rather sophisticated way (especially sampling midi instruments).
I use Battery often, and the workflow doesn't seem too bad, you can drag and drop from windows explorer, but I don't think you can drag in clips from the Logic arrange (can you?). Even when you sample directly into the sampler you still have to assign the sample to a given note, which seems to be all you're really doing by assigning a wav file to a cell from by browsing in the filesystem. It is definitely important to be able to preview the sample easily. The non-destructive editing facilities in Battery can take the place of some destructive wave editing work, but there is still a place for basic destructive editing.
With either an external hardware sampler or the computer I think you'll be faced with the task of keeping samples organized in a given location in some way for the sampler. For some soft-samplers, I guess you don't really have to keep them organized on the PC, but if they are all over the place and one gets moved that probably messes up the multisample. If it is a requirement that you export samples to a given folder before importing them into the softsampler maybe that is a possible bottleneck, but it probably makes it more likely that your multisample will not get broken.
If opening the daw is cumbersome can you just use the soft sampler in standalone mode?