Mr Deux /Teddy
If you suspect airframe / structural damage, the additional buffetting caused by deploying the speedbrakes and/or gear, could further damage the aircraft structure and lead to an in-flight break-up.
For that reason, if you suspect structural damage it is advisable to maintain present IAS for the descent to minimise the changes to the loading.
Yes, the descent will take longer, but it is deemed safer.
Teddy
In both the above cases you would be on oxygen - I think you need to do some more revision.