Dear Naina_Marbus ji and Shri Sangom ji,
Thank you very much for clarifying about Swathi nakshatra. It appears that this nakshatra has something to do with POWER since Vayu represents ultimate power. Perhaps this nakshatra is an example of how to practice restraint when in power, as Saturn the planet who is embodiment of restraints is exalted here. What you both wrote made me think along these lines. I will keep an eye out for further information on this nakshatra as to why certain deities as listed in the OP chose this nakshatra for avatara. Thanks again for your help.
Smt. JR,
Saturn is not "embodiment of restraints". Saturn is a very merciless master/despot when the need arises, as per the horoscope, and, in some other instances Saturn can be a boundless giver, benefactor as well. But whatever Saturn gives, even if niggardly, will be ultimately for the "Sreyas" of the person as different from one's "preyas" - things which one likes, but need not be beneficial, like alcohol, say!
All the 27 asterisms (nakshatras) are alike; the good, bad, worse, worst classifications are mere conventions, imo. For instance, I remember our elders postponing a journey (from central Kerala to Nagercoil) for months because a suitable not-inauspicious day could not be found in the intervening period! The belief in the astrological do's & don'ts was so great then, some 60 years ago. But today people travel to other continents without even looking at the almanac!
As I have said many times earlier also in this forum, astrology and horoscope are only like road signs or indicators. For example if an idiot were to look at a wall clock and conclude that the clock's needles are so powerful that when the short needle passes 6 and the long needle crosses 12, most people wake up and therefore come to the learned conclusion that these two needles have their own intrinsic powers, qualities, personalities, etc., how will we rate that? Hence, the true and correct way to approach astrology is to see the movements of the so-called planets (including Rahu & Ketu - which were absent in Varahamihira's system) as like clock needles indicating the flow of time and what may be expected when the needles are in a particular configuration.
If you take vedic practices, anuraadhaa seems to be the most sought after nakshatra, since every homa commences with the lines —
ऊँ ऋद्धास्म हव्यैर्नमसोपसद्य ।...अनूराधान् हविषा वर्धयन्तः । शतं जीवेम शरदः सवीराः। which form the first half of the Ashtavaakya for the star.