Strictly speaking, you don't need secondary at all, but since it's already there I'll forego the pros and cons. Someone else can rave about that...
So your secondary has no time requirement, at this point all that matters is the dry hopping time. It goes a little faster if it's warmer, slower if it's cooler. I would say a week is enough, assuming it isn't in a fridge or anything.
Regarding force carbing, it depends on your style. Burst method is fastest (30psi, shake/roll the keg, then down to serving pressure). It is fastest, but can cause over carbing most easily and doesn't make your beer "not green" (not that any other method will). Set and forget is the safest, truest method, but requires a couple weeks. Personally, I think a mix of the two is best. Start at 30 psi, maybe shake a little (I don't, but it will speed it up), then lower to serving pressure. I think it still takes a day or two to get where you really want it, but it is much faster than the set and forget method.
Make sure you have a carbonation chart of volumes CO2 based on temp and pressure.
Edit: Or just listen to Yooper. She said the same as me, twice as well, with half the words.