Hi

Performance of MaxDop (maximum degree of parallelism) depends on your hardware configuration and if any other applications running on same server too. If you use parallelism, it will introduce some overhead to small queries. Now it depends on how many db instance you have and what type of operations (select queries & insert/update/delete queries) are being executed.

Regarding indexes, if it suites you, you may use maintenance plan to rebuild indexes on suitable intervals. However it may not solve your performance problems always.

Thanks