What Is The Significance of ANY of these Placements?

You're asking for quite a bit here, but I can elucidate some things for you. What is most important in Western astrology are the aspects created between planets--that is, how many degrees separate them. Conjunctions are zero degrees, oppositions 180, trines 120, squares 90, and sextiles 60, this all of course giving or taking about five degrees. The sign in which a planet is found shows how a planets energy is expressed, but a house will show in what arena of life it is expressed. This is especially important when considering the effects of the slow-moving outer planets, which change signs only once in a generation, and are thus best-interpreted as for as individual personality goes by house placement. A quick Google search will likely show you some good pages that detail what the houses mean. When interpreting an aspect, the energy expressed through signs and houses must be considered, and thus the aspect (and the chart) will have a unique interpretation. With this in mind, you can hopefully see that astrology concerns much more than merely differentiating people into 12 different personality types.