1- no it shouldn't because you're only loosening one set of bolts. The top tree (or bottom, depending on where you're planning on installing the signals) will hold the sliders in place.
2- 30-35 ft/lbs per my FM for a 2001 sportster. I do not know if this torque value changed for your model year. That's all the more reason for you to invest in the best tool you can buy for working on your bike- the factory manual.
Now if I have suspicion a felony's been committed, I can just walk right in here anytime I feel like it because I've got this badge, I got this gun, and I got the love of Jesus right here in my pretty, green eyes.