R/M/S are standard IUPAC ambiguity codes that are shown if you have mismatches/variants at a site. Note that *** indicates an insertion. Underlined reads are either secondary alignments or orphans (hit ? and look at the bottom). If the reads are colored, then that indicates their MAPQ.
I have absolutely no idea what you want to achieve by removing indels or SNPs. Regarding errors, I suppose any difference that isn't called a variant could in theory be called an error and changed in the BAM file, but as a general rule that's a really bad idea. It's best to explain what your actual goal is.
what do the red * indicate?
How do I remove errors/anomalies?
I don't think you really want to remove errors or anomalies. What do you aim to achieve? This is probably not the way to go.