You said “there has been a great deal of doubt cast lately on the dating of the reigns of the early Anglo Saxon kings or leaders in Wessex.” Actually, historians have been well aware of this for well over a century. Numerous Anglo-Saxon authorities have commented on these problems. For example, in 1898 Henry Howorth mentioned problems with dates before 560. He also stated that he believed anything not derived from Bede prior to that time was untrustworthy. [Henry Howorth, The Beginnings of Wessex, English Historical Review, Vol. 13, No. 52, Oct. 1898]. The great Anglo-Saxon historian Sir Frank Stenton discussed these same problems in his book “Anglo-Saxon England,” published in 1943. In 1965 D.P. Kirby, Problems of Early West Saxon History, English Historical Review [Vol. 80, No. 314] discussed these problems in great detail. Kenneth Harrison weighed in in a 1971 EHR article as have many others.So this has been affecting our understanding of early Wessex kings for a considerable period of time. But most ASC scholars have agreed the pedigree begins with Cerdic. But, as to when he arrived, the dating of battles he fought, and when Wessex became a kingdom are all uncertain.
One major headache for modern students of this time period is time itself. They didn’t have a universal calendar. Many used Easter tables (based in part or whole on 19 year lunar cycles) and computed years Anno Domini, which is Latin meaning ‘in the year of our Lord.’ But what year was another question. A year was often calculated from the Incarnation, which was sometimes synonymous with the Conception, but at other times and by other religious entities from the Nativity. Then, the numbering systems themselves did not have a zero. The year 1 BC was immediately followed by the year 1 AD. There is much more to this but you get the general idea, dating anything in Wessex at this time period accurately is a problem.
As for as a newer translation of the ASC being better than an older translation that’s not necessarily true in all cases when you consider all translating is a form of editing. Latin like English has a variety of words which have a variety of meanings. The translator’s function is to attempt, as best as he or she can, to convey the original meaning without any bias, preconception, or distortion of the facts. Alternatively a later translation may benefit from newer discoveries and it can be an improvement. But in the case of the Anglo-Saxon Chronicle there are by most accounts nine surviving manuscripts. Some are mere fragments while others are much larger. Most were written in Old English while others contain Latin or later Middle English. None are the original manuscript. And while some were at some point copies of others, with their own information then appended to the copy, others are significantly different. Which manuscript or combination of manuscripts used will make one translated copy of the ASC different from the next. So a newer translation is not necessarily a better translation when it comes to the Anglo-Saxon Chronicle, it just may be a different translation.
As for your comments on the age of the Anglo-Saxon Chronicle, yes it is that old and it’s also imperfect, but it is the best source of information we have for much of that period. You also asked about hero songs and minstrels, I assume this is questioning the accuracy of oral histories of the time.
“Where culture is oral, memory rules. That is to say, in a pre-literate society, the faculty of memory is all-important for socio-cultural continuity, and those whose memories are copiously supplied—such as the aged—are valued. But literacy does not drive out oral patterns of thought, and certainly does not do so immediately.”
Paul Tankard, Samuel Johnson's "History of Memory", Studies in Philology, Vol. 102, No. 1, Winter 2005.
Essentially in pre-literate societies many individuals were well adapted to accurately recall kings lists, administrative details, laws, and general history and were employed to do so. It was important then to know what happened previous just as it is for us today. But it does seem to be difficult to believe that individuals then could remember what commit to books, computers, and other media. We seem to be able to accept that modern astrophysicists, mathematicians and other professionals in various sciences can accurately remember thousands upon thousands of pertinent facts, yet we can’t accept that pre-literate bards, poets, skalds and others could not accurately remember historical events. But, you have to ask how did the king collect taxes and control expenditures without administrators? And how did these administrators do this without a written language? In fact, these tasks were routinely done for thousands of years in pre-literate societies and were done in early Anglo-Saxon Wessex. And just as tally sticks were used to keep counts, metrical poetry was used to remember history or balladsby scops (Old English poet/historian equivalent to the Welsh Bard or the Scandinavian Skald). Does it work? Well, I can’t remember who sat next to me in eighth grade English but I can still recite the poems I had to learn.
One other thing to consider, we don’t always get the history of a particular people from members of that society. The Angles, Saxons and Jutes who established themselves in Britain were at times written about by native Britons, Franks and others coming in contact with them.
I’d agree that there simply is not a comprehensive history available for the West Saxons from this time period. Their kings and close male relatives (Athelings) are about the only members of his group you can find any information on at all. In a few cases the only information may be his name. Pauline Stafford wrote a very interesting article called The King's Wife in Wessex 800-1066, in Past & Present, No. 91, May 1981, where she made the point that prior to King Alfred, the names of earlier wives are mostly unknown. With few exceptions they had little if any political role and were not considered Queens, just the king’s wife. I’d also agree that anyone tracing their ancestry to this time be very careful with the sources they use. The Internet is full of unsourced and uncorroborated junk genealogy.