Re: Wrong War Table quest for Support Divine
My understanding of how that works (which, granted, is somewhat limited) is you will only get a "support X" mission if they need support. So, if you are taking actions that put Leliana ahead, then you shouldn't need to do a mission in order to boost her point total. Now, say, if you spoke with Cass and said "I'd support you" but Leli has more points, then you would probably get the mission to support Cass, which may or may not give her more points than Leliana.
In the game I just finished, I didn't openly support anyone but when I spoke with Viv I agreed with her that Cass was the best candidate. After that conversaiton, I got the mission to "support Vivienne," which I didn't do. Leliana ended up as my Divine.
You never get to actually pick the Divine. It's all based on point totals from various missions and conversations throughout the game. The best you can do is tell someone you will support them and do the mission if it becomes available.