*snip*
If Fire and Water begin at War, how does that solve any of the Alchemy issues that led to this discussion in the first place? You'd never be able to get into a Water city to even take the quest.
Your 11 skill point example is assuming a player wants to obtain all 12 Marks. Most likely a player will just get at most 2 or 3 Marks to get a specific off-element skill they want. A player who just wants access to a bunch of Marks can always get the UW Mark after all. Each element gets bonuses for being a mono, which thematically means players are discouraged from going outside their element. Making off-element skills easier to obtain and it easier for players to "multi-element" with skills would run counter to the focus of the current system. It makes so sense to encourage easier off-element skill acquisition if you are going to discourage multi-element card usage.
It doesn't, which is why I suggested having all the Mark quests Start at the Omnitron and having requirements closer to the Element's home. (2 posts below my original suggestion)
And you're right, my 11 skill example was an extreme.
Each element also gets a bonus for using 50% of their element, which encourages duo's. Requiring skill points to unlock a Mark AND access a skill tree uses up a lot of skills, limiting duo's to a select few. I'm not trying to go off and build an Air/Life FFQ deck as a Fire Elemental. But diversity in my Duo's is something that I would like.
About the Mark of Underworld. You're right, I could gain access to different marks this way, but it is incredibly unreliable to do so.
This does not actually make Off Element skill trees easier to attain. In fact, it makes it harder. You have to spend the time unlocking the Mark, which is what Male is against. It encourages initial leveling up in your own element, but later as you finish some of these quests, opens up many new options for you.
So while it takes more effort to use off element marks, cards, and skills, I think in the end, it creates more diversity.