I know about reload cancel. Can also cancel the animation but the sounds will continue playing and give you a reload while using the Flamer, but I don't know what the timing is for that and if it's reliable.
I don't do great in Gold, but not entirely bad either. The main problem is it gets boring doing so little damage. It turns the Black Widow into a peashooter since mine isn't upgraded and all of my damage comes Flamering bosses. I don't know if a Claymore II cuts it either.
Hiding reload with Flamer is very reliable. I do it throughout my entire video. It's basically shoot->wait maybe .25 to .5 seconds->Flamer. You'll hear the reload click and see another shot in the clip while you're flaming. It's an amazing way to increase your dps because you're always either shooting or flaming.
Doing little damage with a flamer character doesn't compute. Also, Claymore I is plenty strong for Gold. It obviously gets better, but still plenty good. Also, since this game is so old, there are plenty of good players out there. You should be able to do a Gold PC run in 20-23 minutes with a mediocre team, and that will provide more credits, and more rare cards, and it only ever gets easier.
Also, as others have mentioned, if you're still struggling to survive with the build I mentioned, just play Reapers. Flamer destroys all their units and acolyte destroys banshee barriers.
Another aside, every character is gold viable. Adepts, vanguards (on host), and engineers for the most part are gold ready out of the box, meaning their powers alone allow you to do tons of damage. It would be a little more difficult to crank out the damage with infiltrators and soldiers with lower grade weapons, but you have good ones unlocked, just not maxed out. Also, having geth scanner unlocked so early is a real advantage for you, as it provides so much information that helps you survive.
If you want a build for a specific character just ask and we can give you a build based around your manifest. You already have powerhouses unlocked like Drell Adept (no grenade capacity hurts but isn't necessary), Batarian Soldier, Turian Sentinel, Turian Soldier, Valkyrie, AIU (very survivable), Asari Adept, Slayer, Quarian Male Engineer, and Human Vanguard. They can all wreck on gold without super powerful weapons since they either have debuff, powerful powers, or weapon buffs.