The goblin are part of the main story, but they are less advancing the main story and more an alternate path to the current end. The goblins were a long promised route in the game, I may be wrong but I believe that they were planned to be recruited before the orc camp was envisioned. They are located near the South East of the map, there is place holder text that says "BH Camp". However you can't actually recruit them yet as they are still in early development and only two scenes have been added.
The dev team like to add scene and get feedback on them before commissioning the art for said scene. This means that new scene will be just text on either a black or generic background. Typically the art is added in the next update.
The new Andras x Alexia is part of his NTR path. To get Alexia on his NTR path you need to lower her relationship with Rowan (you can either be a jerk to her or put her in the maid job and have her believe rumors about Rowan), you also need to raise Andras's influence over her (just have her go along with what ever Andras wants) (note that Andras's influence needs to be HIGHER that Jezera's so it is best to focus on one twin at a time), I think there might be a corruption requirement too but you should reach that easily if you are going along with Andras or just generally have her slut it up a bit.
