First, I like that change, it safes a lot of leveling work for alters and traveling (because you can place alters all over the world and use them right from the start for life skilling), but just as a reminder:

I really would appreciate if the above changes sum up all life skill scores of my almost 20 characters in my familiy to a new total family score, instead of just picking the highest score so that the other lower scores just expire without consideration. 

There are players out there with life skill fame (not family fame) of over 10k well splitted over 20+ chars, it can't be that a lot of that work was for nothing. 

As you want to exceed the Guru 50 limit anyways, to sum all the scores up to a total value shouldn't be such an impossibility. It could be easily done by free Life exp exchange coupons.

I agree, the time investment loss for some players will be a lot if they don't "add-up" alts lifeskill levels and give credit.

I'll be happy either way, to be honest, but yeah, it would only be fair to combine xp rather than just using the highest current level.

Totally agree.

I would also like to know what they are going to do with all the Life EXP Exchange coupons (to swap the levels of a single lifeskill between characters)
These coupons are soon no longer usable, and they costed pearls to buy...

You are right, I forgot about that fact. People should get some sort of compensation for that.

99% of them come from the event so there will be no compensation. At most, an option to sell to an NPC at the max market price.

They 100% should raise Guru higher than 50 & merge all earnt lifeskill exp on the account. This way no ones progress is deleted and everyone gains from this update.

For sure, really happy they announced merging them. But I too really, really hope they don't just take the highest and roll with that.

That should be a given. PA wants to do this change to make people happy and not mad.

Here my opinion from my other post:

Generally speaking, lifeskillers can be divided into 3 types: trophy hunter, life fame/guild life point lifeskilling, and normal lifeskillers.

Leveling up alt characters to increase life fame/guild life points was more of a guild-oriented goal striving type of lifeskilling. Where as trophy hunting, where you push your lifeskill levells as high as possible, is more of a personal-oriented way of lifeskilling.

If PA now introduces family-wide lifeskill levels, it basically means that the fame/guild lifeskill lifeskilling is abolished. PA is removing something from the game without replacement and ignoring the passion and love of an active player base that participated in that activity. 

My Suggestion: The best solution I've read and can think of myself is to simply expand the current lifeskill level system instead of replacing it. In the 'My Information (P)' window, introduce a "Family-wide" tab for lifeskill levels, while keeping the "character"-based tab (the one we have currently in-game). 

Lifeskill fame and guild life points should remain the same and be calculated the old way with the "character"-based lifeskill levels from all of your characters in your family. While the new "Family-wide" lifeskill levels tab is used as actual stats for your character. Your family lifeskill level will be calculated as the sum of all character-based lifeskill levels of your family.

In other words, keep the old system, while introducing family wide lifeskill levels!