hi
Maybe i am not a spriest specialist but i play one and i see he have few problems here.
For first spriest arent great in single target fights like this 2, he have problem with malkorok flex trinket(it is useless for single target fights).
For single target figths he should replace malkorok trinket with anything..atleast timeless island int trinket. same with his first ring. timeless isle ring can be better. ofcourse i am talking about 535 ilvl items.
For upgrades he should start with weapon and then trinkets. Only if he have much more valor start upgrading other items..but for now he should farm more valor and wait for new weapon or trinket or normal set part.
One more thing for his gear. he need legendary cloak fast.
My tip for spriest is work on your dot uptime(on Sha vampriric touch was below 40%.. when it should be near 95). Dont pick divine star as 6 tier talent when you didnt use it at all. Halo is best choice there.
He should read some guide for example from icy-veins.
Tell him to download addons from curse.com atleast Shadow Priest DoT Timer, HaloPro and Weak Auras and learn how to use them.
Ps: Sorry for my bad english i hope it will help you a little
Ps2: Dot uptime one more time!!