Listing pros and cons is a good start, I see that you've more interest in pursuing pHD than to worry about your career. This opportunity to study pHD coincides with your career, plus your company agreed to fund your pHD and promoted to the Director level, which is a great bonus!

I am for pursuing your pHD; because ultimately I see that you would find pHD to be more fulfilling, plus you get to continue your career later on. Don't worry about the "What If's" (such as unable to complete pHD or new manager or age). Deal with them when the time comes. Thats my 2 cents though, if you're still unsure, you have to ask yourself this one question,

1. Can you foresee yourself being capable of balancing between work and pHD? pHD students in my uni dedicated full time for 4 years. Adding career/work into the mix might increase your overall workload.

TL/DR: I am for pHD!

This post has been edited by RisingTide: Aug 18 2015, 12:53 PM

The time frame for pHD is broken down into few parts,

Data Gathering + Analysis + Writing Thesis.

Writing thesis takes a month (two months max) according to my friends who have pursued their pHD. Data collection and data analysis is the most time consuming part, which is why most pHD takes up to 4 years.
I have a friend who will be pursuing her pHD in finance, and she told me her about the time frame of her pHD, that it would require about 1 year to collect all the necessary data for her model.

Since (assuming) you've done most of the initial work, you've allocated more time for subsequent phases (data analysis) or to be used up as spare/buffer time for your career.

The only worry you have now is to be able to come up with a proper time management, or a work/phd schedule.

Care of share what are you other worries besides career workload?

From what I've read I can see that your heart is fixed on pursuing your pHD, but your mind is weighing out the pros and cons of future events (once you've undertaken your pHD).

I'd weigh the pros and cons of my decisions (that would affect future outcomes) to a certain extent; however I always kept reminding myself that "no future is set in stone", and I would always make the best out of my situation.

I tend of overanalyze things that would ruin my day, hence my advice is to keep things simple; focus on your main priority, and everything will eventually falls into place.

This post has been edited by RisingTide: Aug 19 2015, 11:48 AM