Well, for chromosomal translocations Microarray is pretty poor. it shows you loss and gain of material but not where the material is.  for translocations, your best bet is karyotype if larger than 2Mb (visible by banding), or translocation specific FISH probes (break apart or fusion), or sequencing (but thats overkill to be honest).

2) FISH tells you the number of gene copies you have so it can tell you amplification but it cannot tell you about RNA levels or gene expression levels. For that you would want to do qPCR or RT-PCR. 

3) yes, a point mutation in KRAS is usually determined using targeted sequencing of just that gene.  If there are hotspots for mutation (for instance always in exon 1), sometimes sequencing of only the likely exon will be performed (like the V12 common mutation)

4) gene amplification is most commonly determined with FISH. PCR will tell you expression level increases but if you want to know how many copies of the gene you have, FISH is the way to go.

5) Flow is the best. it is hard to do IHC on suspension cells. you can do IF on cells that are cytospun onto slides but in reality, most people sort by flow. using CD3 to gather T cells and then CD4/8 to subtype them