... Lab tests have never proven evolution. Only micro evolution which has limits.
If by evolution you mean speciation (i.e. reproductive isolation),
new species have been bred in the lab, and speciation has been observed in the wild.
Thats right so there should be many more dumb mistakes visible in the fossil records and life because there are many more than there are rare positive good ones.
You should remember that fossilization is extremely rare, so we only see random individuals of a small selection of species. Individual mutations are extremely unlikely to be distinguishable in the fossil record because representative samples of the relevant population are not available for comparison, and the vast majority of mutations would not be distinguishable in fossils even if such samples were available.
Obvious physical distortions are usually caused by injury, disease, or developmental abnormalities. Mutations that are 'dumb mistakes' will generally mean that the individual will fail to reproduce successfully, or will produce less viable offspring, so it's unlikely that more than a handful would be available for the rare chance of fossilization for a very short time, in contrast with the bulk of the population to which they belong, and their faulty gene(s) will not spread through the population. Mutations occur in individuals, evolution occurs in populations.
Remember mutations are errors. They basically cause harm and are not good for us so a so called beneficial one is very rare.
Not so; the vast majority of mutations are neutral - they do not affect the individual's environmental fitness. As mentioned above, detrimental mutated genes will generally not spread through the population - unless they are
recessive and only detrimental when both alleles are the mutated form (e.g. cystic fibrosis, Tay Sachs), and/or the single allele mutation comes with a beneficial advantage (e.g. Sickle Cell Trait), but these are relatively rare - and they would generally not be distinguishable in fossils (although Sickle Cell Trait might be).
... we should see the landscape littered with the many more negative ones that also come or even more so the neutral ones hanging around somewhere.
Negative mutations mean less fit individuals whose genetic lines are brief, if they survive to reproduce at all. They will not be represented in the population (except as above), and so are very unlikely to appear in the fossil record.
It seems such a hassle having to accommodate all that extra harmful stuff just to get a tiny rare benefit if that. In fact there is evidence that even the so called beneficial mutations come with costs as well. Its like taking one step forward and 100 back to make things better.
Whether you think it's a hassle or not doesn't matter. Individuals of most species produce a large number of offspring with minor variations (including mutations). Only a few of these offspring survive to reproduce. Many die by chance that is not related to their potential fitness, but in general, over the generations, the ones that survive do so because their particular variations make them more likely to survive. The ones that survive to reproduce supply the genes of the next generation, and so the fitter genes will spread through the population as more of the surviving individuals carry them.
Fatal mutations don't get passed on, and most beneficial mutations provide only a slight advantage; it's extremely rare that a single mutation provides a large advantage because the vast majority of traits are the result of the complex interactions of many genes. Nevertheless, change can occur rapidly in relatively small, isolated populations under extreme pressure. One example seen repeatedly in the fossil record is when large creatures are isolated on an island (e.g. a peninsula becomes cut off). In this situation, limited resources and strong competition tends to result in a rapid decrease in size of the individuals, resulting in a pygmy version or species. This is known as
insular dwarfism. The inverse effect (insular gigantism) can occur for small creatures, where resources are plentiful and predators absent, e.g. the Dodo.
