Showing a happily married couple is boring to the viewers. Even Ali cheated on Ruby. Regardless of his sexuality, Finns character is supposed to be whiny and unlucky in relationships (which isn't such an uncommon thing with people in their 20s). And Aaron is single because he's in love with a married man. Watching him come back from France and finding his happy ever after within an few months would be so boring to watch.
Yes, being dead is very stereotypical. It even happens to straight or bi people. And I still don't see the point of Darren having AIDS. It was just a plot device and there was nothing more to it.
Aaron doesn't have any money. How would he pay any rent? And who would he live with? Adam (how also lives at home, btw)? I think it's not that uncommon for people in their early twenties to still live at home, until they can afford more.
You really think Hollyoaks has done a great job with Ste and John Paul? The couple that keeps cheating on each other, one getting AIDS (one of the stereotypes you mentioned earlier, btw), getting his female best friend pregnant, them getting married anyway only to break up five months later? This is your type of perfectly portrayed gay couple without any stereotypes? I actually stopped watching them because it became so unbelievable.
I think Robron got a lot of screentime during the first months of their storyline and the other couples/storylines need development, too, so they have to take the backseat for a while. It's a soap with many plots, not just the Robron-show. I'm really looking forward to them returning to the screen, but I'm ok with the break for now. Compared to other characters, they've had a lot of screentime.