Very helpful to have them all laid out in this way.
By studying whole genomes, scientists came up with a date around 1200 AD, which nicely coincides with the brutal slaughter of the Jewish population of the Rhineland.
This is Shai Carmi's 2014 study.
http://www.nature.com/articles/ncomms5835
Some analysts in the pop gen world have quibbled with his mutation rate, and the generation age, and using adjusted figures come up with a date of about 900-1150 years ago. That would date the bottleneck to the original settlement in the Rhineland.
https://westhunt.wordpress.com/2014/09/09/ashkenazi-ancestry-revisited/
The total number of ancestors would grow, in the second case, from 350 to 300-500. Of course, that's not total number of people who survived, but total number who passed on their genes.
https://westhunt.wordpress.com/2014/09/09/ashkenazi-ancestry-revisited/
As for the R1a lineage, 800 BC is when the Assyrian Empire conquered Israel and reached its broadest extent.*
The V88 is indeed puzzling. I don't know if I can find the reference, but in one of the papers that investigated the back migration into East Africa of groups from the Near East, the authors expressed some surprise that there was still a Sardinian like population in the Levant or passing through it at the rather late date they were estimating for some of this movement south. Perhaps V88 was late moving south into the Levant?
*Ed. The Assyrians were eventually conquered by the Medes and the Persians. Some of the members of the so called Lost Tribes, with some cuckoos in the nest, might have been absorbed by the later Babylonian captives, and later returned to Israel. Wow, that's pretty fanciful for me, but possible, I suppose.