To clarify, I fly for EZY.
There are recommended PA's but you can add or remove things from them as long as you cover the safety elements, there is no SOP for PA's but training is the same across the board so you'll tend to hear roughly the same thing.
The landing lights turn off after flap retraction because they create drag and at high speeds there is no need to have them out during climbout.
The SOP for Landing lights on descent is only "can be turned on below 10000' but should be on by final approach". We do this in several ways, if we forget, lights come on after gear down by PNF action, if we don't forget we normally ask for them sometime before but close to localizer interception.
In some situations they come out to help us descend quicker, if you're left high, the lights add some drag that helps get down or slow down quicker. In Madrid or anywhere where airspace is busy and they do parallel approaches you turn them on earlier than normal to help be seen.
That's mostly it.