As for recoloring doors, I've checked, not all can be recolored YET. Those that can't be are the simplest ones (and the tweet I linked hints they'll get more colors in some future patch).
Anyway, a few times, I've sent one of my sims on a jog. When he took a while to return, I found him doing this...
Also, a while ago, I've completely rebuilt the house and created some kind of "romantic corner" to be used for weddings (you've seen how poorly some sims chose where to stand in a screenshot I posted a while ago.
I think the space rocks are a decent touch, but the most important thing is that the guests have no option to choose some weird spot half a level lower than the wedding arch.
On the other hand, the graveyard and observatory in the background are not as good fit.