My Illuminas hiss as well and I didn't notice it on the old HPs I had installed. I've understood it to be normal, but it's also possibly due to bad seals (though I have it on both rears).
Check for leaking strut oil.
Unless the bearing has a lot of play in addition to being worn (causing noise), then you probably won't feel it.
The tire could have a belt shift (perhaps as a result of that flat) - try moving it to the rear or other side (if non-directional) and see if the noise follows.
They should work just fine, but with the slightly higher (about 20% stiffer) than stock, the stock ES dampers may wear faster (your mileage may vary). Physically they fit.