I have noticed (and perhaps I am wrong because I don't talk to many Khajiit) that none of the Khajiit seem to have a title like: Ra, Dro etc... or at least very few do. Is there a lore reason as to why they have none? I thought perhaps it was simply because the sub-species in Morrowind and sub-species in Oblivion have a different culture but, I looked it up on the UESP and it seems they all share the same culture...

http://www.imperial-library.info/interviews/jobasha.shtml does a good job of explaining Khajiiti naming patterns.

[edit] more clearly, few khajiit have titles because few deserve them. most of the khajiit we encouter in OB are simple lower and middle class folks, not special enough to earn a title. Either that or they arent conected to their culture anymore. i'd think that proper Ta'agra naming is much more common in Elsweyr.

And possibly more common in Vvardenfell since many Khajiit there were taken directly from Elsweyr, as opposed to growing up (haha, let's just pretend) in Cyrodiil?

exactly.

As an aside, I'd never been sure if khajiiti was in fact the proper adjective or whether I'd just pulled it out of thin air, so thanks for clearing that up for me.

Most of the Khajiit are just named "Bandit" or "Highwayman"...

Of the 50-60 named Khajiit within Oblivion, 9 use J, Ji, or Ja, representing young advlt status. 5 use M or Ma, indicating apprenticeship or virginity. 8 use Ra, Ri, or R, indicating a title of respect (although some, such as Rancid Ra'dirsha, might be using the word improperly). 12 use "S' ", or begin their name with an SH sound. Only 2 use the Dro sound. Of course, there's no saying whether or not there are obscure titles we have yet to be introduced to -- K'sharr, for example, doesn't fit any of the known titles, but fits the typical pattern. Or it could just be part of his name. 65% isn't that bad.

There's probably a cultural thing to it, as well; http://www.imperial-library.info/interviews/jobasha.shtml suggests that it considered foolish to use two titles, such as J'-----dar, but a few Khajiit in Morrowind and Oblivion do anyway. He also said that those who select a nickname with meaning in the Khajiiti tongue usually don't find the use of titles necessary.