How can I decide Rebuilding Index with DETAILED or SAMPLED on SQL Server
I would prefer to rebuild the indexes where the fragmentation percent of the indexes is greater than 30% and a Re-org of indexes where fragmentation percent is in between 9% and 30%.

Coming to update stats, I would prefer to do it with Full Scan depending on the size of the databases.

While these are resource intensive database operations, I would prefer to do these operations over the weekends or after business hours.

For Production Environments, I would usually setup jobs and allow them to run over the weekend.

Please go through the below link for maintenance plans(very useful) and customize accordingly to your environment.

https://ola.hallengren.com/