Swap partners for a week? Yes. It's always interesting when they do that on DWTS to see how the celebs respond to coaching from a different pro partner. How often have we said that we wish Celeb X could be paired with Pro Y instead of Pro Z? This is a chance to see that.
Same sex partners for one week? No. It would be more of a gimmick than anything else. If a celeb were to have a same sex pro partner for the whole series, that would be one thing (although I still think it would become more about the hype than about the partnership and the dancing) but for everyone to have a same sex partner for one week just for the sake of it? It would be presented as a total gimmick. And what if any of the celebs or pros are uncomfortable with it? They've come on the series expecting a partner of the opposite sex and then suddenly, mid-series, this gets thrown at them? It's hard enough for the celebs to adjust to a different partner for one week without adding that element into the mix as well.