Should I restart the instance after adjusting Memory Allocation and MAXDOP?
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.