"Will a low output pickup actually help to give more tonal properties to your guitar?"
Boonster,
I think that's a very good and valid question. It was something that I asked myself and which I found the answer (I think) after trying out a whole bunch of pickups.
Here's my humble take, your mileage may vary:
Higher output pickups have more windings, and that leads to a more limited frequency response. They have more output, more gain on tap. There's an emphasis on the mids/lower mids and bass. Less articulate, less clarity. They have their uses, and excel in certain genres, but for my taste, I largely prefer lower output pups for playing the blues.
Lower output pups have less windings, and I find that that gives a much wider frequency response. They have lesser gain, lesser output, with focus on the higher mids. More articulation, more clarity, more presence, more chime and they just sound sweeter to my ears.
Currently for my designated 'blues' guitar, I am using the Lace Sensor Holy Grails and Hot Gold.
For me, my ideal blues tone is almost clean, but with a slight giving of gain. Something that is almost at the verge of break-up, but not quite there. It has the tonal properties of a nice chimey clean tone that retains the sweetness and characteristics of your guitar, but just enough gain for it to break-up when you dig in and pick hard. Touch-sensitive and dynamic. The articulation and presence must be there, so that all your nuances and subtle touches can be expressed.
I link articulation very closely to presence. Imagine speaking with your hand covering your mouth, people can probably still make out what you're saying, but it's not very clear. That's what I call a lack of presence. Now speak without covering your mouth, it's now much clearer and well-articulated, that's presence for you.
Of course, there's no hard and fast rule about what a good blues tone can be. Buddy Guy uses a hell lot of gain, but he still manages to be one killer blues player. Then there's also that gritty, raspy tone that some guys have. At the end of the day, it's going to take some time and experimentation to find out what you really love and want. But I hope my post here might have helped in some way to point you in the right direction.
Whatever tone you end up with, make it your own. It's just a tool for you to express yourself and your music.
Cheers!