I've got about 2k rounds through my Rival S and its been flawless with Blazer Brass. I just bought a case of Blazer Aluminum and had one failure to extract in 100 rounds. All I shoot is 115g. I'm hoping that the aluminum rounds end up working better than that preview.
With regard to the mag...
I'm a fan of the Holosun 507c units and they're reasonably priced compared to some units. Since the typical red-dot is just a prism and laser emitter in a housing, it's not complicated and shouldn't cost many hundreds. Yet there are units that are way up there.
That "get what you pay for"...
For a gun lube, I've been using Mobil 1 synthetic motor oil (I think its 15-50w). I use an applicator bottle with a needle tip. Only a drop on the specific sliding parts.
I find that it depends what deposits you're cleaning up. I use Break Free CLP for a lot of things. But I have a compensator on my .22 that leads up frequently.
For that, I use a 50/50 mix of 3% hydrogen peroxide solution and 5% distilled vinegar. This makes peracetic acid that is quite...