I don't believe that your timeshare will apply to the MegaBonus because you didnt pay the hotel directly and simply using your Visa for incidentials is not going to work. It has been discussed on here alot!
35K-50k points would not be worth spending out $75+ a night on a room just to get there. IMHO you have too far to go to make it beneficial.
I would try to go with the free nights.
Happy Travels!