What are the details regarding the 10-year (5+5) Non-Immigrant O-X visa in Thailand?

There would not appear to be any flexibility regarding any split between the amount of income and the deposit in a Thai bank so e.g. if your income is 1m baht per annum and had a 2m baht bank deposit, that wouldn't be sufficient. The detail on the website you posted also indicates that you still need to attend at immigration every year in order to establish that you continue to qualify, so although they tout it as a 5 (+5) year visa, the reality means that the differential between that and a traditional visa is even more marginal.

This website explains it pretty well (y)

Most thai consulates and embassies have information about it on their website now. It's the Non-Immigrant Type O-X visa.