I wanted to scribble down some observations for those who have newly unlocked Skirmishers and are trying to make sense of the class.Update: I have won the game now, once, on a Stonewarden.
The 'Feel' of Skirmisher.2017 update: Picked the game up again and had a nice run up to the Shade of Telos and played sloppily; greedily trying to finish the fight after clearing adds instead of resetting it by going up stairs and renewing cooldowns. I've lost a few high level runs here. Seems to be a lesson I never learn. Small edits that I might update later if I actually get a win on this race/class combo.
Switching a piece of gear (preferably) with the Quick Hands prodigy with an affix, I think its called 'Deep Breath', that lets you restore half your stamina is mandatory. This class, even with the remedies in its kit is still stamina hungry as hell. Stamina scumming with the Deep Breath gear lets you go heavy armor (you'll still need Pace Yourself, the cooldown on Deep Breath is pretty long).
Edited guide to remove the advice to level constitution, use gear instead to qualify for thick skin & get +HP gear to achieve survivability. Constitution has a very poor return and is a noob trap I've fell for for a very long time. Hopefully DarkGod buffs it.
Hunt down a high range sling as a priority, spend gold if you have to. The 9-10 range increases Kill Shot damage into the One-Hit-Kill mark vs most dangerous mages and some random rares.
Use a teleportation rune, drop a shield rune.
I took the poison catagory for the poison that reduces healing because I ran into two fights where I was being outhealed by the boss (the notable one being the naga boss in the Temple of Creation). Skirmisher damage isn't massive and some fights can be fairly drawn out.
I still had a spare Catagory point left over after purchasing rune slots and Poison. It felt bad but in the end I sunk it into raising the Called Shots catagory.
With the new ammo reload mechanics all archers classes have been given more incentive to 'kite' their enemies i.e. shoot then move, shoot then move. Skimishers have been given Vault and Tumble (and passives that improve them) to make them fun kiters. However Vault will get you killed if you use it to leap foward into the fog of war because as an escape it puts you further into danger unless you do some planning.
The way to deal damage with this class seems to be via 'proc' or 'on hit' effects. Bash and Smash, Hurricane Shot, Bombardment & Knoggin Knocker are multi hit talents; some with unimpressive ratios. So, when you are appraising gear favor inferior proc gear over other superior options.
Races (or my apologies for not having a decent rundown on race synergies)
Unless I'm going for a particular unlock I play Ghouls on all my classes (Unless they completely lack a regen mechanic). It's my favourite race and they are alot of fun with Skirmishers.
Pros
- Ghoulish Body and Trained Reflexes stops 'WTF?!' damage spikes outright. You will never walk around a corner and be instagibbed by anything.
- The 'Offensive' clensing runes favour ghoul skirmisher playstyles so you won't grieve for your lack of incriptions; True melee fighters have a hard time without heroism, healing, regen and movement infusions and delicate casters are too squishy to have the correct positioning required to get the most out of Acid Wave and Biting Gale. Robust and mobile Skirmishers strike the right balance.
- In addition the instant rune blasts make up for another weakness of skirmishers: weak AoE damage.
- Ghoulish Leap! Another kiting tool and more of those are always welcome.
Cons
- No Antimagic

- Global speed -20%

- Healing options are thin on the ground. You are relying on Tireless Combatant regen and Shielding Runes. You will want a solid shield rune, a teleport rune for resetting boss fights + three offensive clensing runes. Note that you don't get massive damage spikes on a ghoul; it will often be layers of damage over time debuffs that will kill you.
If I had to play a non Ghoul I would avoid Halfings because you get enough crit via the skirmisher kit and a high cunning. Halfings are only good on classes that arn't going to raise their cunning IMHO.
Prime Stats
Dexterity > Willpower/Cunning > Strength to qualify for armor.
First you are focusing on Dexterity first to qualify for better sling damage talents. Ghoulish Body will raise your Con high enough by itself to snap up the first level of Thick Skin. Get enough cunning to qualify for Kill Shot and be able to keep raising it while at the same time working on your willpower for stamina and health regen. Use Con gear to nab the last levels of Thick Skin
Talent and Generics rundown
Talents:
Technique / Buckler Training (1/1-4/5/0)
This is unreliable damage mitigation, the skill that deflects projectiles is golden however and great to max turning many enemies who would be a nightmare into a joke. Smash and Bash is your best early game nuke and your only 'GTFoff' me button for enemies that have closed into melee after that you should start considering Vault/Leaping away to kite because some of your stamina/life regen will be denied while you have enemies at personal range.
The last talent seems like a dud.
Technique / Skirmisher - Slings (5/1/3/0-5*) *only raise bombardment once you have Capacity+ bullets and a piece of Deep Breath gear or you'll run out of ammo and stamina.
Hurricane shot needs to be raised quickly to 3 at least for ten AoE shots; its nice to Quick Hands switch to Sling Bullets that have a 'Blast on hit' effect as those 10 shots will overlap and help clear large rooms of enemies. This is the only skirmisher AoE option in the kit

Technique / Tireless Combatant (5/4/5/4)
Hard to find the spare points to qualify for & level this tree but its something you need to do eventually. Remember to try and keep enemies non-adjacent.
Cunning / Called Shots (1-4/5/1-4/4)
The first talent in this tree is great even at 1 talent point and will often be your ranged opener.
Kill Shot is your Best nuke surpassing Smash and Bash if cast at max range; use Tumble to get the best damage. One of its best uses is vs necromancers and summoners who fill up the screen with minions, or dangerous wizards who hide behind bruisers that need to be taken down pronto. None of these skills require direct line of sight; marvelous.
Cunning / Poisons & Cunning / Traps
I picked the poison category for access to the reduced healing poison which I felt was necessary.
Generics:
Technique / Acrobatics (3 or 4/3-5/5/4)
Tumble doesn't improve at level two (ignore the crit bonus, that's not why you are taking it) and only becomes useful at level three and four. Note that it is instant like a chronomancer's phase door and functions mechanically similar and won't suffer paradox failure.. albeit it is much shorter. It is great to set up Kill Shot or as a Line of Sight breaker.
If you have reached zero ammo try tumbling behind an enemy (an instant action) then vaulting back before sprinting away to quickly reload up. Then you can turn to fight again. You can turn 45 degrees after Vault without the run speed dropping off. Managing your ammo can be tedious and the main challenge of this class. One of your first goals is to hunt down a decent ammo pouch with the 'Capacity' modifier so you have approximately 60 shots to work with.
Undead / Ghoul (5/3/1/0)
Max Ghoulish body pronto to qualify for early Thick Skin for free as well as being able to slap on the armor that you like. Get Leap to 3 which should be good enough. Skirmishers have no synergy with Gnaw.
Prodigies
Quick Hands for, among other things, stamina scumming with a piece of Deep Breath(I think that's what its called) gear that restored 50% of your stamina.