Wow, that's alot of ??,,
I hope you've read the accurizing tips in the FAQ's, every answer is found in there.
There is no single fix to a forearm that magically makes a handi shoot better, some it helps-others it won't. I've used a variation of the RTV bedding method in two and it's helped alot.
For proper pressure and screw torque it's a matter of experimentation to find what your rifle likes, some will use a torque screw driver purchased at a modest cost,,I went with the set screw in the bottom of the lug, all I need do is turn the screw down till it stops. ( the set screw cost 49 cents )
Basically the forearm work is much like any rifle when you hear about barrel whip and bedding. ALL barrels move when fired, it's about finding a balance of several "rifle" issues, the neat thing with the Handis is all of it can be done at home and with "tinkering" groups can shrink. As with all most all guns "handloading" for these things can make a huge differeance.