Hi Tim, welcome to the forum.
Your question is too hard for me to answer fully - I've only used one BKP strat set so far, the Irish Tours. I play them through a POD XTlive and studio monitors. I chose them because I play mostly blues and blues/rock.
I'm finding the ITs very versatile - they do work well on my more "rock-metal" amp patches that were mainly set up for humbucking guitars.
For me, they also clean up nicely - but "crystal clean" I'm not so sure about - not something I tend to use a lot :lol: I'm usually looking for that warm, live, just-breaking-up, sort of Strat sound.
Having said that, I've been experimenting with sounds this weekend, and I am planning on trying to create a "clean" patch that I like - and the strat is what I'll be using. I'll post again if I find something amazing I didn't know about these pickups!
In my strat, the ITs respond very well to volume and tone control use (I'm wired for a master tone) - and there is a huge variation in tones I can get with the guitar controls alone before touching the amp settings.
On the hum-free question, they're just like other strat pickups I've used over the years - hum comes with the territory, if you want "that" sound. And I think this applies to all of the BKP strat pickups. You just need to make sure the guitar's shielding is up to a highest standard possible if the hum worries you. I've never bothered though...
You can order the middle pickup RWRP (reverse-wound, reverse-polarity) which gives you hum-cancelling in positions 2 and 4, and increases the strat "quack" in those positions slightly. I did this with my set (partly because the Texas Specials I was replacing have the same), but I didn't really need to - even though I play in the living room with the TV and a computer on at the same time! Yes, I get some hum, but no more than on any other standard single coils.
Hopefully that gives you a start, and some other folks with wider BKP single coil experience can chip in. I'm certain that Apaches are going to get mentioned for crystal clear (I'm actually planning on getting a set myself for another strat).