I'm sure others will give more feedback.

from my point of view having data and logs on the same drive are not necessarily bad - all depends on the workload.

If nothing else I would do the following

-Change maxdop to 8

- ensure maxmemory is set

- ensure Instant File Initialization is enabled

-Ensure that cost threshold for parallelism is not set to the default value of 5 – something around 50 is normally better but final value should be tested

-Buy a set of SSD drives and move the tempdb to those

- ensure tempdb has at least 4 files, 8 probably better on that machine spec

-See which trace flags are enabled

-Myself I normally set the following ones instance wide

---1117 - tempdb

---1118 - tempdb

---1222 – lock information

---3226 – remove backup successful info message

---4199 – enable all fixes