The Mather1's page

Bit of both. I try to go with what makes sense, as well as what synergizes well.

For the most part, it means I do fairly typical race/class combos, but with a twist in the actual build. Though one notable exception was a Changeling Shaman I made, who turned her racial talent for witchcraft towards more natural pursuits.

Sounds like you've got damage covered, but will be lacking in healing and utility.

You should ask your Gunslinger if he plans on taking on the role of party face, if not then Bard or Skald would be good choices.
If he is planning on being the face, then I would recommend going either Alchemist, Investigator or Witch.

Inspired Blade Swashbuckler, then get yourself Fencing Grace into Two-Weapon Grace. Only x3, but you'll be critting several times per turn with DEX to DMG.

If you wanna be a tanky healer, a good option is Oracle, which has plenty of Mysteries that make them suitable as front liners. And if you're really keen on multiclassing with Barbarian, you then have the option of taking the Rage Prophet prestige class later on.

Also, for the spell-eating sword. One option that's available regardless of class is to fuse a normal sword with a Rod of Cancellation using permanencied Aroden's Spellsword.

You can hire almost any spellcaster to do that for you and from then on you have a permanently antimagical sword. Bonus points because since the sword now acts as a rod of cancellation, it itself cannot be dispelled by anything other than a sphere of annihilation.

15th Magus (Bladebound, Spellblade, Hexbreaker)
Dispelling Strike, Disruptive, Reflection and Spellbreaker Arcana.

Summoner (Synthesist)
Flight Evolution

And for the whole "magicless" part (not 100% right, his antimagic seems to be more like a corrupted form of magic), just do buff spells with a range of personal.

Vigilante.
I like making highly gimmicky builds, usually focused around things not intended to actually be practically viable, so being able to essentially make my own class from scratch is a huge boon. I also don't like being bogged down with resource limitations, like spell slots or x times per day abilities, which the Vigilante avoids almost entirely.

After that, Fighter and Brawler.
Again gimmicky builds, afforded by a plethora of bonus feats and archetypes that change the core functionality of the classes.

Can abilities or effects that affect Magic Items be applied to Constructs, or does Constructs' status as Creatures render such effects inapplicable to them?

The ability that brought this into question is the Salvage feature of the Artificer class by Adamant Entertainment, but the question is also applicable for purposes such as the Disable Dweomer feat from the Advanced Class Guide and the Sabotage Magic Item feat from Ultimate Intrigue.

While I must credit you for that information, you seem to be forgetting a slight thing when it comes to firearms in Pathfinder; you use the same Alchemical Cartridges in Coat Pistols as you do in Double Hackbuts. If you were to try that in real life, the morgue attendants would be picking pistol fragments out of you for hours and half your arm would be gone. The realism only goes so far.

Also whether a rifle can realistically fire an alchemical cartridge is slightly beside the point, as break-action shotguns like we most likely have in Pathfinder don't have the weakness of a sliding part.

These Advanced firearms aren't even equivalent to modern ones, they're from somewhere in between the colonial and cowboy era. Since there's only one size of metal cartridge and it doubles as a shotgun shell, this means it's the same size as a paper cartridge. Now with that in mind, I'd say yes, you could load a paper cartridge into a rifle as long as you take account for how to ignite the powder.

What I'm saying is that advanced firearms are the only firearms that have a standard reload speed of a move action and that alchemical cartridges specify that they can make a move action reload speed into a free action, adding two and two together there says advanced firearms can in some way use alchemical cartridges and that they get the bonus to reload speed.

(a full-round action becomes a standard action, a standard action becomes a move action, and a move action becomes a free action)

I'll rather trust a rule that's written black on white here.

I'm fully aware of what they're based on, but there's nothing in the rules against it, and the only errata I can see regarding firearms is about the size penalties.
Furthermore while alchemical cartridges are described as paper cartridges, it would still be possible to create metal cartridge versions, essentially making the Dragon's Breath alchemical cartridge virtually identical to its real-world shotgun shell equivalent.

Also I've found nothing against reducing the reload time of Advanced firearms, rather it is all but stated by how it is specified that move action reloading is reduced to taking a free action.

There is no rule saying it's not an alchemical substance however. And even if it was specified as one, it's rather unlikely that it would be listed as an alchemical item due to the fact that it can only be used as ammunition.

This twin-barreled shotgun can be shot either one barrel at a time, or both together as one attack.

You can fire both barrels as a single attack, then reload as free action because advanced firearm with alchemical cartridge, fire both as single attack, reload as free action, fire both as single attack.

It's pretty much a living nuke. It makes 3 attacks per full-attack round, which again is multiplied by two as it fires with both barrels at once, making for a minimum of 68 damage (1 on all damage rolls, enemy succeeds on all reflex checks) (would have been 92 with Deadly Aim) to every enemy within the cone as long as they don't have damage reduction, immunity or a way to dodge completely. Also the initiative is +7 to make sure the enemies can't do anything before they're set ablaze, increased to +10 and 88 damage with Reduce Person Extract and a Dexterity Mutagen.

The idea came to me when I noticed the Fire Bombardier INT bonus after having toyed a bit with firearms when I helped a friend build a sniper Gnome.

Friend in question here:
1) "Cartridge, Dragon’s Breath
This cartridge contains alchemical compounds that, when fired, produce a cone of fire instead of the normal attack of a one-handed or two-handed firearm with the scatter weapon quality." - http://www.d20pfsrd.com/equipment---final/weapons/weapon-descriptions/ammun ition/alchemical-cartridges/dragon-s-breath-cartridge

2) That was actually my first choice, but Jen here said that wouldn't work so I had to go with a Slate Spider.

3)Point Blank shot should not require an attack roll as the modifier to attack rolls there is a bonus, and the prerequisite is just being within close range of the target. Deadly Aim takes a penalty, but it is stated in such a manner that one would believe it was an effect of the attack rather than a kind of trigger.

4) Yep, Double-Barrel Shotgun, not the cartridges themselves.