SNMP Write Access to devices

SNMP Write Access to devices

I am new to opmanager and SNMP in general and have a few questions I hope you can help me understand.

Is security a big concern with SNMP? Or should I stick with the default "public" and "private" community names?

How much access does OpManager need? If I only enable the default public read, will I be able to do everything in OpManager? What does write or change permissions in SNMP get me?

Thanks for the info. Any thoughts on the subject would be appreciated.