Yes, you can select which updates you need in Tools → Plugins → Updates.
A complete cleaning of SNAP cache would mean cleaning:
C:\Users\[username]\.snap
C:\Users\[username]\AppData\Roaming\SNAP or C:\Users\[username]\AppData\Local\SNAP
C:\Users\[username]\AppData\Local\Temp\snap-[username]
(depending on what directories from the above listed ones you have)