I like how it is now with companions being bisexual or playersexual. It is fair to all. Everyone has the same number and type of romances. I like to match my pc to companions based on personality and actions/alignment. I wouldn't want a good-aligned pc to not have any good-aligned romance options. However, a companion should reject the pc if the pc has done things the companion strongly disagrees with.
They could add more companion friendship dialogue to the party. I think that would help the feeling of the party a lot.
Agreed. I really like the idea of more relationship-building-but-not-romantic dialogues with companion characters, too. It shouldn't just be "do the romance to get a lot of extra story content with this character, or get nothing". There should always be some alternate type of relationship you can pursue with them that isn't sexual. Like becoming good friends, or some kind of mentor/student thing, or like a protector/protectee thing (like Minsc and Aerie), or even rivals who compete over everything.