GE, let me try to provide a more measured comment.
Firstly, I agree with your sentiments.... poor operational risk management (a more contemporary name for "airmanship").
However, you are running the risk of suffering from "holyer than thou" syndrome. As a probationary Ppruner you need to understand you'll receive a lot of stick for such posts. Particularly given you are from from one of the "majors". This is an obsevation rather than a criticism! I personally think you would be better to consider this situation as such.....
Lets look at the facts:
1. Heavy Rain - Doesn't neccessarily stop a flight if vis is acceptable and standing water is considered in the takeoff calculations. It does of course increase risk.
2. 10kt tailwind. Right on the limit of most airline operations I have been involed in over the last 30 odd years, but not OVER the limit. However, once again increased risk - particularly combined with the rain and an intersection departure.
3. Lightning strikes around the field. This indicates that the thunderstorm is certainly deemed to be "at the station". Some airlines prohibit operations when TS are at, or near, the field however not all. We would need to have insight into the airline SOP's to pass judgement here.
4. "Almost" standing water on the field - there either is or is not standing water. You can't be just a little bit pregnant. Most performance charts I have used have standing water allowances. Again, however, if standing water was indeed evident risk has again increased - hugely, given tailwind, intersection departure and TS.
5. Windshear. I have never been able to "observe" windshear so I'll substitute that for "Forecast and Reported". This is the most damning factor in my view. I don't know any airlines that do not prohibit departure in reported windshear, but again I'm not familiar with both of these airline's SOP's. Certainly the risks associated are in the very high to extreme range if operatring around windshear.
6. Vis - about 1,000m. Well above most takeoff limitations I am aware of for jet operations. At least double the low vis crteria. Risk increased? - certainly, particularly combined with all the above.
7. Finally, asking for taxi clearance whilst still connected to a tug. Never seen any SOP's prohibiting this. Most "checkies" would jump on you for this, but this relates only to "technique" not "procedure" - unless your airline precludes it via SOP. In fact many operators regard this practice as a mitigator agaist a very busy ATC on the ground frequency. However, risk of not ensuring the ground personnel are disconnected before taxi is higher - but managable by most crew with good SA and common sense. The problem here, I guess, is that common sense is the least common of all senses.
So the point of my post is that it is possible that these operators were within SOP's. As a consequence your "preaching" to them could well fall on deaf ears. It could just result in "us and them" mud slinging.
I will support your premise, however, that these sort of activities can indicate questionable "airmanship", and are certainly indicative of a less than mature safety culture.
We deal with risk everyday in our industry ("threat and error" we normally call it). Having the ability to recognize that risk is accumulating, and applying mitigators to control it, is often the most poorly executed aspect of our job.
Having said all that.... great to hear that your approach to the conditions indicates a mature approach to safety. I'm just suggesting you take a similar approach to your posts to avoid a "pprune attack" resulting in the message being lost, which is often the result in this place.
Stay safe!