We already have had Oghren twice. I don't ever need to see him again. Although, I wouldn't mind a letter updating us on what he's up to. Is he still with Felsi? How is their kid? Is he still in Amaranthine with the Ferelden Wardens?
Since they only give us 1-2 prominent dwarves per game, I'd rather them bring us some new ones in the next game.
Same here. I wouldn't mind a mention either, since I do think the poor guy deserved at least a mention on the War Table or codex. I'd even vote for him as a temporary companion if/when we go to Weisshaupt. There's little doubt in mind that we'll end up there either as either the Inquisitor in a DLC, or in the next game. The writers couldn't have dangled that sequel hook harder if they tried. 
I could see him contacting the Inquisitor that he's gonna look into "somethin' weird." I wouldn't object to hanging out with him for awhile, and see how he's doing. I was never a big fan of his, mainly because of Awakening. Alcoholism and family abandonment played up for laughs was a disservice to the character. Now that some time has passed (most of the people I know aren't exactly the same as they were over 12 years ago,) hopefully the choices my Warden helped him finally get his act together.