Salarian Architect: Is he viable in Gold?

He's quite good now. They buffed his Remnant VI a while ago. Put points in that first and take the missile evolution to detonate. Use a priming ammo.

Salarian Architect is a beast on Gold. My personal favorite build is 66661. Put one point in support system and max everything else. Take VI rank 6A detonating missile, barricade rank 6B electric defense for priming, incinerate rank 6A detonator. Find a horde of red bar enemies, put barricade down to paralyze them then use incinerate. Sit behind your barricade to enjoy the explosions and shoot to finish anyone who is still alive(if there is any). It's a squishy glass cannon build but strong enough for Gold IMO. If you prefer a more defensive build maybe try maxing support system and 1 point in barricade.

He's pretty good with the Sweeper.

As far as weapons, you can play him a lot of different ways.

If you want to go combo-heavy, you can use a high-RoF weapon with ammo to prime and detonate using Incinerate (if you spec into 6a Detonator) and/or his VI (if you take 6a Detonating Missiles). You can also take a lower-RoF, high-damage weapon like a sniper or shotgun and go to town while your VI pulls aggro. Either one works well.

I strongly recommend a 1-point-in-Barricade build. It's an ability that does pretty much everything you need it to at rank 1, so additional points are largely wasted.

So you're saying not to go the Detonate route? Most are recommending it so I'm curious why you do not.

Probably difference in playstyles. Double Incinerate is effective without any ammo or priming. At long ranges and short ranges. With radius it can nuke and kill things close together in one shot(eg. spawn of 3 red bars). Both fireballs can hit the same target--you can force this to happen on any target by just shotgunning it at a closer range, and occasionally it just happens on its own at long range. This will instantly one shot red bars.

Still take the detonate missile on the VI. I just leave barricade at one point.

There is no time for areal bombarment, so ... take the Naladen! It is fun. Allies will love it ...
A more conservative choice is to take pistol (SMG) with the expert package. Hurricane is no brainer if you have it. Eagle, Equalizer, Talon, even the Charger.
ARs are not bad Thokin, Ghost, Avenger-S. Or take the raptor if you don't have any of this.
Or if you prefer to snipe behind your barricade then take the vanquiser (still good), BW, valiant, inferno, shadow (very good).

Without reading everything else on this post I would say yes. I just have the one point in Barricade but still make use of it.

I run him on platinum. He is somewhat squishy when the vi dies, but with the durability upgrade it is very tough and does a rather outstanding job pulling aggro, especially boss units, which tent to try using their melee attacks on it, but don't deal enough raw damage that way to take it down fast.

I went with a 6/6/6/4/4 build I think, Though the passives are a bit flexible. Shock barricade + vi missiles is really good at cutting off doorways.

The only thing to watch out for is that the close combat upgrade, (+100% health and stuff), does make the vi go off and do it's own thing, which can be really useful when during hack it pulls half the enemies to the other side of the map, making it better than most randoms. Of course, sometimes it lures the enemies around the flanks and right behind you when it is grumpy.

ET is so inconsistent in what it effects that I decided bollocks it.

I don't really feel like I am doing significantly less, though if I was using ammo to make my gun benefit that might be different.