Test-E/Deca - First Cycle Feedback

Stats: Age 25 5"9/177lbs BF 10%ish Have been training for the last 5yrs or so, on and off. Last 18mnth have been where I have seen the best improvements in gains, dieting and lifts as I’ve done more research and been super consistent. This will be my first cycle and I was looking to gain 15-20lbs and improve the numbers on my lifts.

Have spent a lot of time over the last few months researching to make sure I am as prepared as I can be going into this cycle and that I have the programming of it right. Am not worried about staying super lean during this as the goal is to put on as much LBM as possible. Have switched from a Split to PHAT Lifting Program and have enjoyed the change up recently and look to continue this when cycling.

Week 1-12 Test-E 500mg/wk
Week 1-10 Deca 250mg/wk
Week 1-12 Arimidex .25mg EOD
Week 1-12 Caber .5mg 2x/wk
Week 3-12 HCG 250iu 2x/wk

PCT
Week 15 Clomid 50mg 2x/day
Week 16-18 Clomid 25mg/day

The standard first cycle seems to be 500mg of Test-E, so I have gone with this. Have also chosen to include Deca at a mild dose both for the increased bulk as well as to combat joint injuries.
Had a few questions I wanted to ask;

Caber - It’s there to protect against Progesterone from the Deca.
Should I run this by default, or only use if it begins to cause sides.
At 250mg a week I’ve read that it shouldn’t be as much of a concern.

14Wks? - I also have enough Test to run this for 14wks
Is this too long in your opinions or should I make the most of it?
Have also thought about keeping it to 12wks but frontloading instead.

AI - I have heard it mentioned on other sources not to run the AI unless you experience sides,
but personally I would like to run it just incase. Thoughts?

Appreciate your suggestions and feedback.