[quote]What is the exact number of glassed UNSC planets?[/quote]No exact number is given but the majority of them were glassed. That means hundreds were glassed by the Covenant. [quote] is there a source that confirms a solid estimate?)[/quote]For glassed planets? No, however there were around 800 UNSC colonies by 2525. [quote]How many casualties (civilian and military) are known?[/quote]On October 20th, 2552, approximately 23 billion casualties were sustained in total, with billions more during the battle of Earth. [quote]The main question I want to know based off the previous is, have any canon sources indicated UNSC plans of recolonization? There must be a far lesser amount of habitable planets now since the Covenant destroyed most of them.[/quote]Yes. Extensive plans are underway to colonize new worlds. There are two Halo 4 maps that actually take place in the early stages of colonization. (Interestingly, despite the massive casualties, billions were displaced as war refugees, a large bulk of which would return to repopulate Earth.) Daybreak takes place on the planet Oban, during an ONI Op called Operation: DAYBREAK. Erosion takes place on a colony world (name escapes me) with unusual seismic activity. The human structures set up are there to determine if the world is suitable despite the seismic activity. [quote]Also I was a little confused with the forerunner books, was the origin of the timeless one confirmed? (I heard he was a precursor, or a flood version of a precursor, or just the flood pretending to be a precursor).[/quote]I've discussed this quite extensively with my other lore buff friends. Looking over all the info, we end up back at square one where we literally have no idea what it is other than it being some kind of Gravemind. [quote]Were the flood confirmed to have been created by the precursors to "test" civilizations?[/quote]No, the Flood arose out of an accident sometime before 110,000 BCE. (The process took over 10,000,000 years though.) With guidance by the Primordial, it does seem as though the Flood is serving in the role of testing humanity for the Mantle. However, they had a major goal of destroying the Forerunners utterly, something they succeeded in, even if they survived. [quote]Finally, do we know what any of the surviving Spartan IIs are doing (during the Halo 4 events)?[/quote]No. We do know after being rescued from Onyx they were given the option to join the SPARTAN branch. A choice they seemingly declined. However, the Halo 4 EVG notes that there are unconfirmed reports of SPARTAN-II personnel being seen in the field with MJOLNIR MK. VI. [quote]I don't remember the date of the UNSC getting into the Onyx Dyson Sphere to save those trapped inside but it was a little before 4 right?[/quote]Yes, they were released in March(?) 2553.