Pretty sure it's being sent to Langley Mill for scrap or something along those lines. As you say, it makes sense to as it no longer has a MOT, and is the last of the Citaros left anyway which was suffering a lot of issues constantly.
Thought most/all of the buses were fitted with a system to prevent the tyre issues as much as possible. Depends what the issue was though, if it ran over something sharp and burst a tyre, then I suppose that wouldn't be preventable or at all controllable (please feel free to correct me here though if I'm wrong)!
Red arrow is certainly handling alright at the moment especially with 74 being a dedicated spare (the less we mention 73 the better). Think the main issue with the Versas on sixes is the steep hills and obstacles en route wear them down quite a lot compared to other ones. Not even considering they are used for a fair chunk of each day and are on a fairly demanding set of routes as well!