That is your problem right there. That server is dead.

I'd argue that experienced pilots wouldn't run that tactic, but I'm afraid that isn't the case. Aynway, even if you are loosing while trying to crack the fortress, it is more fun than sitting there and trying to snipe along with your fellow players. At least you get the Death Star trench run feeling

Especially in Lost Shipyards the bombers are so often in front of the GS that they are not even a threat to the scouts...

Doesn't need to be a battlescout. I eat through this kind of fortresses in my Novadive quite nicely (using Distortion Field, Running Interference, Targeting Telemetry with Evasion upgrade and Power Death to weave through enemy lines). But you need support from Ionrailguns and you definitly don't want to be the only scout. And you need to be willing to die a few times (I don't mind because getting ammo for the pods can be difficult, as I see too many T2-Bombers running their Repair Drone without ammo refill). It also helps to target the GS in the back. Usually this leads to some heavy fire when the enemy Gunships all turn around to get you, but this allows your team to get into better position. And if they don't turn around even better. Just shoot them one by one. But I still think that the tactic of this fortress is boring and not good use of time. Especially if it ends with two teams doing the same thing. It takes forever and is as far away from fun as trenches can be.

What ability should proc? I haven't played Scrapper in ages, but going over the discipline path I guess only Backblast procs - and that is a lvl 68 passive.

Well yes, but Shadows/Assasins really need to keep up the buffs and as the relevant abilites are on different cooldowns you kind of need a rotation for those. Rest is filler (read: can be ignored if you have something better to do at the moment). Damage is not the concern of the rotation I listed above.

Only use Maul when it is procced (Conspirator's Cloak lvl56 passive). The problem with the dummy is, that it does not help your force management which leads to you needing to fit in saberstrikes which do not proc the stuff you need (and you will never get a procced Discharge on a dummy). Tank rotations rely on being hit, you can not avoid that. The easy rotation is: Shock->Wither->Discharge->Thrash->Filler->Shock->Filler->Depredating Volts with fillers being Assasinate/Maul (procced)/Thrash/Saberstrike in descending priority. A more advanced rotation would move Shock around and use Discharge only depending if you got a proc for each. But you can go far with the easy one.

Depends on the spec. I guess you are talking Focus/Rage? Anyway, I've just checked it on my 69 guardian (Foucs) and the initial hit is around 150 (which is the hit of Freezing Force), the dot ticks (Persistent Chill) after that are somewhere in the 1500 area if not criting. So maybe you just looked at the initial hit?

Just tested it. It does trigger.

APM is actions per minute, so that includes the use of CDs - most of which are off the GCD. I've seen parses where people even used thread drop on CD, which increases the APM in a way where you could argue if this still is a valid parse (what ever that means) regarding APM. It is also dependend on the situation (dummy, boss fight with lots of pauses, PVP), the discipline and the amount of alacrity in your gear.

Are you a Sharpshooter beyond lvl 26? If so, Penetrating Rounds replaced it.

As stated above, IO uses Missile Blast in (sub 30%) rotation, but it also uses Explosive Dart to spread one of the dots (Serrated Shot). Both are nice tools for healers doing dps, too.

Why choose? Play both! Arsenal is everywhere. You can do well with it and it is easy to play decent. For me it is too boring so I play IO on my Merc, but that's me. Lethality seems (in my perception) to be the least played discipline in the game. But boy, is it fun - though I prefer Ruffian myself, having started it back in 1.1. It can dish out high damage with great consistency if you know what you are doing and know the fights. @Cookie: Only the devs can answer that question and I'm certain that they won't, no matter how often you post this question across the forums.

Crystals?

Scoundrels in general have a second ressource, which they need to manage: upper hand. Both damage disciplines need it to do their main attack. And it is only granted by blaster whip (or it's replacement for scrappers), using backblast (or point blank shot for ruffian) from stealth, killing an opponent or using the offensiv cooldown pugnacity (healers generate it differently, but they can use the same as above, too). Ruffian also uses sanguinary shot to gain upper hand. Blaster whip and point blank shot both need you to be in 4m range and I'd say you should use blaster whip almost on cooldown. But apart from that, there are three moves you can do from 10m (mostly brutal shot and sanguinary shot, but also quick shot). Brutal shot is your main damage dealing abilty, and having the ability to dodge voids and still use it is great. The same is true for sanguinary shot and as it also grants you upper hand, you can do more brutal shots from that range. Your dots, flurry of bolts and thermal grenade are 30m abilites which allow you to do some damage at range. As ruffian you want to keep the dots up all the time. And I forgot to mention blaster volley, which in theory can spread your vital shot to other targets it hits. But hitting something with this ability is a kind of art... Summing things up: You need to be close to your targets to keep your upper hands up, which you need to deal the most damage. But you can weave in and out of this range should you need to without loosing too much - though you might want to practice that a bit.