Some more on resin vs plastic
Resin needs superglue or epoxy as an adhessive. Regular plastic cement will not work since this acts to weld two pieces of plastic together.
Resin may produce models with much crisper detail than plastic and can have detail in underccut areas impossible for the injection molding process.
Resin figures have the sharpest detail among plastic and metal figures., IMHO.
There is evidence that the dust from sanding resin may have long term health risks. Care needs to be taken when cleaning up these pieces.
Resin kits are more expensive than standard plastics since they are made in limited runs and the mold has a shorter life span than the injection molds. Resin is also more brittle than regular plastic and generally requires more clean up due to its being poured into a mold. The curing process may leave many tiny, hard to correct air bubble holes.
As was mentioned, you will find resin kits and conversions the plastic manufacturers have never touched.
To your question on paints. The newest generation of acrylics, Vallejo and Andrea, may give results to rival oils in figure painting. ModelMaster and PollyScale are good for both brush and airbrush painting. I personally have no use for Tamiya and don't want to get iinto my rant on that paint here. Suffice it to say you have much better options than this.
Acrylics dry much faster than enamels, much less oils. This reduces the abiilty to blend them but smooth effects are possible. They tend to clog airbrush nozzles more quickly than enamels. That said, since they are water based, clean up is much easier and they are safer, environmentally and from a healrth persepctive since they don't use petrochemical solvents.
In short, resin kits and plastic kits are not competing for the same market but are complementary to each other. The choice of paints is a matter of prefernce.