Inserts are fine if you tighten up the screws evenly on each side & make sure to check that the crosshairs are still in line etc whileyou do it. Hand tight using a good allen key is fine & as with all rings don't overtighten else you risk stripping the threads. The inserts do a great job of centreing & gripping the scope evenly without marking. In my opinion all rings should use this system! When you've finished, just try to rotate the scope by hand. If it moves then you know you meed to tighten them up a bit more, but usually rock solid by this stage. Oh & remember to check your eye relief before tightening as well else you'll have to do it all over again ! I don't ever use loctite on scope ring screws, but as long as you use the right type then that's up to you.
Finally, S&B 8x56's are great, you won't regret buying one (I've got two 1x 25mm & 1x30mm).