Should I restart the instance after adjusting Memory Allocation and MAXDOP? As far as I know adjusting Maximum server memory and Max Degree of Parallelism does not require the instance to be restarted. Will new settings always come into effect without restart?
Both of those server configuration options do not require a restart of the database engine.  Running RECONFIGURE will be sufficient in this case.

exec sp_configure 'show advanced options', 1
go
reconfigure
go

exec sp_configure 'max server memory', 12288
go
exec sp_configure 'max degree of parallelism', 4
go

reconfigure
go

-- the new configuration has taken effect


Please see BOL for reference.