Considering that I don't play RS legit, I'll probably be botting RC as my other bots (hunter with high ban rate) and sw (doesn't get 2x xp) wouldn't work.
BTW, one of the things with this is that technically, even if your saving way more money by "halfing" your $ required for say 95 prayer, your halfing everything, so what you do doesnt really matter.
EXAMPLE:
Player makes 20k xp/hr runecrafting and wants to earn 200k xp. Player makes 100k fletching xp/hr fletching and wants to earn 1m xp.
1m xp fletching = 5 hours (for double xp)
200k xp runecrafting = 10 hours (not with double xp)
15 total hours.
1m xp fletching = 10 hours (not with double xp)
200k xp runecrafting = 5 hours (double xp)
Either way its still 15 hours. Basically, just because your doing a skill that "hard" to train doesn't mean anything.
Basically, as long as your doing something, what your doing during 2x xp weekend doesn't matter, as all of it is just "1/2" or what it would normally be.