hi mate,
here it goes
"takes a deep breath"
ok,
my mate had the same problem with his gas, all you have to do is ignor the bottle hissing and screw it all the way is, and it will be as right as rain,
the bolt wont move without having the right pressure, but thats already been said;
the clicking is probably the solenoid, myn does that too
im not 100% on a SLG's eyes, but with my ion, when u strip it down there is a small circuit board built into the firing chamber, to clean the eyes just take it out and give it a wipe (this may not be the same for a SLG);
for the trigger setting and o ring info, its best to read the manuel. even if you think you know a section, just read the whole thing cover to cover, be suprised at what you might learn
the manuel will also have all the firing modes, and how to change setting.
hoped this helped!
mac