Run paper filters like the rectangular redline ones and then run socks. There is a noticeable difference.

I'm not sold on the paper filter theory and if there is any sort of accumulation, to that effect then it is negligible and not contributory to the carburetors going out of tune.

The oiled foam filter elements should be oiled so that they are coated and not saturated, they should also be washed regularly. I insist you avoid paper element filters, there is good reason why the high performance gear is foam filtered. If you oil them right, use the right viscosity oil and wash them regularly they should serve you well. An air box with a replaceable paper filament is very neat though.

When the carburetor goes out of tune this is largely due to the linkages slowly loosening, slipping or going out of adjustment (worse case scenario is they bend but this is a sign of another issue altogether). Your carburetors will go our of tune from general wear and tear but this is over a fairly extended period of time- we are talking worn throttle shafts, hesitant bearings, twisted throttle shafts and such so this only happens over an extended period of time (looooong term).

The mixture adjustments can also change slightly but this depends on how well you isolate the carburetors from vibration (soft mounts) once again fairly minor change (unless you have another issue that accelerates these changes). A good set of softmount will do well for vibration isolation and thermal insulation. The phenolic spacers from Toyota Mikunis, Bpro and Nismo are my favourite. You can also argue that an aggressive cam brings the shakes on hard and subsequently contributes to a quicker decline in the precision of the adjustment, that's being a bit finicky though, ignore that.

So generally if your throttle linkage gear is fairly simple, like the ones offered by bpro, nismo, datsun competition, sytec, magard you will have fewer moving components and therefore fewer moving parts to loosen up. Loctite on the throttle linkage arms (adjustment nuts) is a good idea but generally I don't adjust from those, I just set the adjustment from the idle screw, set the throttle arms and then go from there. The redline kits mount off the manifold and they aren't as robust as the integrated throttle bar linkage setups like the bpro/nismo/datsun competition manifolds, so they are more prone to going out of adjustment. May I ad, I think the newer redline gear is absolute shyte.

Generally after you first set them you might find that the linkages do move a little bit as they are pressed hard when you go for WOT, and they do move over time so a readjustment quite soon after you first have them running is quite normal. This readjustment will almost certainly only involve just synchronization and not a mixture adjustment (unless required).

The truth is they only go out of adjustment if the adjustments don't stay put, a carb can't really just go out of tune just like that, something normally has to move (or break or bend or twist).

It's a shameless plug, I know, but if you need help with the carbs to be rebuilt I can help you with that here. Mind you I'll be in the tropics for the next 3 months so not possible until next year.