Also, the entire reason behind making death real in the game was to make it more like a real world. Thus having real sex makes perfect sense.
As for the Asuna development, so while they could have fleshed it out so is it still pretty clear if you look back at the earlier episodes. The main point is that while we do have have progress made during the time skipps, so are the main changes to Asuna's character done in the episodes. We have Asuna previous episode pretty arbitrary without asking for kirito's oppinion deciding that they should spend some time together, but this actually started already at the end of the Murder arc episode, with her deciding that they should have dinner together. You just have to draw the logical conclusion that during the time that passed in between those so was there more of the same.
This show is rather extreme case of only show not tell. The upside is that the plot will progress quickly with no need for lenghty explenations about everything. The downside is that you have to accept what is shown as reallity on faith alone.
[edit]I didn't consider that an actually spoiler as it doesn't reveal anything at all.