Have you downloaded the 465B service manual? (The 465 is significantly different)
1: probably normal
2,3: insufficient information
4: Volts/div scales.
Quite possibly dirty switch contacts. To clean them, first switch them many times to see if that moves dirt.
The Tek gold finger contacts are fragile if abused. When switching them fails, take a strip of smooth paper, put IPA on it, open contacts, put wet paper between contacts, close contacts, pull paper away from the contacts being careful not to bend the fingers.
5: not sure what you mean.