On topic of romances, so far the elven companions in the main DA game were always LI (Zevran, Merrill and Fenris). This doesn't mean that the two elfs will surely be LI, though I think there are good chances.
I'm personally not interested in which companions will be LI though. I'm more interested in seeing the companions and their backstory.
I think it's a really good bet that the two elves will be LIs. The formula seems to be that there's one human LI for each gender, which is 'safe', and an LI from a different race which is a little bit different and has been elves so far. Mind you, we only have two games to judge from and two games don't really make a proper pattern.
I do wonder if there won't be more than four LIs this time around, but some will be restricted by race. Possibly. Maybe. It just seems like a missed opportunity not having Iron Bull a romance option for qunari Inquisitors, I guess? (That's if he is even a companion, though I think there's a near 100% change he will be.)
*scratches chin, speculates*