A few things to note about your build.
Explosive strike>static strike, it adds AoE and weapon damage, which is more valuable.
Phoenix fire linked on mines means it applies to the mines, not you, making you miss out on the absorbtion it gives.
Use components to get 100% amor absorbtion, this helps with surviving physical damage, since you have low armor and phys res.
CC resists are low, but thats just a purifier issue.
Low hp, can be pumped up a little bit higher.
https://www.grimtools.com/calc/q2m4d5mN
I made some minor changes to your skills, components and devotion attachments.
Do with it what you will, preference matters more than the ways others build characters.
As for learning how to do crucible better, Ultimate Guide To Crucible Speedrunning - CoD 3b/VB Edition
Although listed as a speedrunning guide, it contains things usefull for anyone.
Hope it helps