1 - To proc Time Dilation, you normally use it to refresh MoT and B Barrier ASAP when in trouble and both are on cooldown.
2 - HP/OA/DA >>> Pitiful %Aether damage and the AS/CS doesn’t help in this kind of build where most damage and buffs comes from cooldown skills (Shadow Strike, ABB/Lethal Assault and Bone Harvest/Soul Harvest)
One more question. I am level 50 now and about to start elite. I use shadow strike and blaDe burst (maxed) but I run out of energy fast. Also I’m pretty squishy, when should I spec into necromancer?
You can do it now and get Spectral binding. Rush Soul harvest for flat dmg. Play it cold dmg with cold devotions and elemental storm until lvl 94
The rest is just good resists balancing
build looks fun, I want to try this build, what skills should I focus on first ? any tips would be appreciated 
Finished leveling this, and it’s a lot of fun; goes through mobs very quickly and the MoT+TD combo makes it pretty tanky in most situations. Great build, one of my favorites right now.
Hello, is this build up to date? Looks super fun and not that hard to farm
Doubt it since the last post was in 2018.
Is it possible to tweak it up to today’s standard?
Maybe. I’m no good at builds though. Maybe have a look in the Build Compendiums and see if anything in there comes close to it.