Controller Based WLANs

1) Given that the controller populates RSSI information in client-view table ('show ap virtual-beacon-report') from every heard probe requests only when they are greater than -65dBm,
Is this threshold hard-coded or configurable?
 
Show ap virtual beacon report will contain all the information not just probes heard above –65 dBm. The client view is an AP neighborhood view from its associated clients perspective.
This is different (subset) of the AP-to-AP view using ARM scanning.
 

Q2. Does controller trigger bandsteering on an AP even though it has different SSID for each radio? (e.g. 'SSID1' on 2.4GHz and 'SSID2' on 5GHz)

If its a single band SSID, then Virtual Beacon Report will have ONLY the radio advertizing the SSID the client is connected to.

in other words, Client Match is ESSID-aware and will not steer client to 5G if the 5G radio is not advertising the same SSID.